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synergy11
02-27-2007, 12:25 AM
Hello to all.

I have been having trouble with modelling a groin vault also known as a cross vault.
I searched high and low on the net and in forums for tutorials but none can be found.

Picture of Vaults (3 good ones at bottom)
http://en.wikipedia.org/wiki/Groin-vault

I'm using XSI but if someone can explain it in there program I 'll try to figure it out.

The closest I came was using bolean operations of two arched segments or hallways...but that led to problems I could not fix.

I'm sure someone on these forums can do it ...i've seen these types of vaults modelled in CG environments before...even in video games..so it can't be that hard once you know the proper way to approach it.

Thanks a lot for any help or links to tutorials.

glib
02-28-2007, 07:28 PM
Well my first post here, I thought I'd try to help. It looked easy enough to me at first, but it turned out to be fairly difficult as I got into it. I'm not sure if there's a simple way to approach this, but I couldn't find one. I'll try to describe my method as best I can.

Started with a cube, then drew a cv curve in the shape of half of the arch. Extruded along this curve, with 9 divisions (for a total of 10, the same as the picture you linked). Then took this arch, mirrored it across and merged the verts at the peak, and scaled it out to give it approximately the proper depth. The duplicated, and rotated it 90 degrees so that the pieces crossed eachother. Went into side view and manually made the cuts along the intersection of the two archways with the split poly tool. I only did half, with my intention being to mirror the other side across later. After the cut, I deleted the polys on the inside of the arch that I just cut. This led to a few more problems, a lot of duplicating and mirroring only to realize another problem, and so forth. I did eventually end up with the right shape in the end, but my method was really quite ugly. It also took me nearly an hour to smash out.

I didn't take screenshots as I went, but they would probably be useless to you even if I had since I backtracked and tried so many different approaches along the way. Perhaps start by creating the arches the way I did, and try the manual cut. Post screenshots of where you get stuck and I'll try to push you in the right direction.

I don't seem to be able to post an attachment, or I would show you what I ended up with.

ridix
03-01-2007, 12:29 AM
My thought is to construct the vault from two half cylinders crossed at 90 degrees. Cut the cylinders where they intersect from top view. It will be two cuts that look like X. Erase unwanted polygons. And stitch the vault together.
I made an image but I don’t know how to display it. I am new here too.

glib
03-01-2007, 05:40 PM
Okay, after reading the FAQ it appears that I need to have my first 2 posts validated before I'll be allowed to post an attachment. So here's my second post, then once it's validated I'll post what I ended up with.

My final model is fairly accurate to that wikipedia image, it's just my method is entirely too convoluted to explain in a tutorial format. I can answer questions when you get stuck though. My one major sugestion is to make manual cuts instead of booleans, which tend to be incredibly finicky in maya. I know they work better in XSI, but they're still a bit of a hack IMO except in very specific circumstances.

glib
03-01-2007, 06:24 PM
There we go.

[edit] Well I think I attached my images, although I can't see them...
[edit #2] Ah there we go.

synergy11
03-01-2007, 10:54 PM
Hey that's great it looks right on.
What's the total poly count for that object? Or is it triangle count?

Anyways this is what I got so far...just need to find out how to cut off the unwanted stuff.
I started with a cube and one be one scaled the verts in x and z only to get the gradual slope than duplicated 3 others and rotated etc..

I'm going to go over your previous post to see if I can follow it...ill let you know how it goes.

THanks for helping.

synergy11
03-01-2007, 11:07 PM
A few more tough ones...

Go here and check out Rib Vault.
http://www.pitt.edu/~medart/menuglossary/INDEX.HTM
It 's very close to the groin vault

synergy11
03-02-2007, 12:38 AM
Hey ridix could you display or go into more detail about your method...i made the cuts but i don't see where you could get that shape.



Thanks

glib
03-02-2007, 12:46 AM
You talking to me, or to ridix?

That rib vault just screams extrude along curve to me. Shouldn't be too tough to do like that, as long as you take care about the number of segments you make, and you plan it a bit.

[edit]Poly count on my arch is 248. I'll try to put some pictures to my words sometime in the next 24 hours.

synergy11
03-02-2007, 01:26 AM
Thanks that would be great!

kirigoi
03-02-2007, 02:16 PM
Hi Synergy, this is a neat little problem. I hope you don't mind if I give my spin on it, as there may be an easier way than how I think glib is doing it. I'd be interested to see a breakdown of your solution as well though glib. I've used Lightwave here rather than XSI, but I haven't used any exotic modelling tools, so I'm sure you'll have access to the same techniques.

Booleans aren't the way to go here, as you'd be intersecting two barrel sections, both of which come to a point in the same place (at the top of the arches). This is likely to cause serious problems and a lot of clean-up after the boolean operation is done. There is a much easier way however:

Whenever you start a model, it helps to look for symmetries that can speed up your model. In this case there is a 4-fold rotational symmetry around the point where the two arches meet in the centre, in addition, the columns themselves have 4-fold symmetry.

First, draw a profile for your column, including the profile of the arch at the top. Do this around the origin so that we can easily lathe it. This profile represents the shape of the diagonal arris, so you will need to make it wider than you expect (or you can model the profile of the arch then multiply it horizontally by a factor of √2) . I've shaped it so that I'll get a slightly pointed arch, but you can create a more rounded arch by changing the shape so that the profile becomes horizontal at the top.
http://www.skylight3d.com/images/CGTalk/screens/groin_vault_01.png


Lathe this out with 4 sides around the y axis to get a square column and arch. You'll have to rotate it by 45° around the origin when the lathe is complete to bring the column back in line with the x/z axes.
http://www.skylight3d.com/images/CGTalk/screens/groin_vault_02.png


Make a note of the x & z coordinates of the furthest point of the arch (in y is up coordinate space). This will be the top of your arch. Move the column by the negative of the values you just noted to put this point on the origin. This a view looking down on the column. The black outline shows the starting position, and white shows where it's been moved to. One edge is now along the x=0 axis, and the other along the z=0 axis.
http://www.skylight3d.com/images/CGTalk/screens/groin_vault_03.png


Mirror this column on the x and z axes. The points to be joined for each side of the arch will now be at exactly the same coordinates. A merge points command will now join the arch sections together.
http://www.skylight3d.com/images/CGTalk/screens/groin_vault_04.png


And a perspective view of the result:
http://www.skylight3d.com/images/CGTalk/screens/groin_vault_05.png


This block of columns can be cloned to create larger supported spaces. In the image below I've cloned the arches a few times in one direction, and flattened the sides of arches and columns that aren't leading to further columns:
http://www.skylight3d.com/images/CGTalk/screens/groin_vault_06.png


Now I've placed a few walls and a floor, and replaced free-standing columns with cylinders that look a little nicer (you could do this in your first step if you want them to all be cylindrical).
http://www.skylight3d.com/images/CGTalk/screens/groin_vault_07.png


A quick test render to show the result. The total scene has a little over 2000 polygons, mainly as I've included cylinders, and the curved surfaces I've used are a lot smoother than glib's.
http://www.skylight3d.com/images/CGTalk/screens/groin_vault_render.jpg


I've done this very quickly (less than 10 minutes modelling time), but if I was to improve things, I'd spend a bit more time in step 2 refining the column shape, adding rounded edges, fluting to the column and perhaps some decoration to the capital. None of this will effect the technique as listed above as long as you make sure the top of your column is still square. If you wanted to have hollow arches and show the view from above like glib has done, you could add some thickness to the top of the arches at this stage as well. Just make sure the edges that are to be joined are flat and lie along the x and z axes. Let me know if you don't know what I mean and I can show you how.

Hope this helps... M

synergy11
03-02-2007, 05:35 PM
Thanks for posting kirigoi.

I'm getting on this right away and i'll let you know how it goes.

glib
03-02-2007, 05:43 PM
God, I thought I posted all this last night. I must have hit preview but forgotten to hit post. D'oh.



Make a cube and a curve.
http://www3.telus.net/public/liamg/step1.jpg

Extrude along it, and rotate the verts/the face at the top right until it's completely vertical so that...
http://www3.telus.net/public/liamg/step2.jpg

...you can duplicate across, combine and merge verts, and scale out to give it some depth.
http://www3.telus.net/public/liamg/step3.jpg

Duplicate again to give you a temporary arch to use as a template, roate this 90 degrees and scale until the bottom corneres overlap in the fashion you want.
http://www3.telus.net/public/liamg/step4.jpg

Using an orthographic view (side or front, depending on your layout) make the cuts on one arch, delete the inside faces, the underside faces, and the edge faces, until you have just one surface. You can repeat this cut on the other side if you like, but I just deleted the extra polygons once I had one side, mirrored across, and merged that one vert at the peak. I also deleted the underside and edge faces on my helper arch, but this is unnecessary because...
http://www3.telus.net/public/liamg/step5.jpg

...delete your helper arch (the uncut one), duplicate and rotate your cut arch 90 degrees, then combine and merge the verts along the joining edges.
http://www3.telus.net/public/liamg/step6.jpg

Finally, select all your faces and extrude down to give whatever depth you need.

More divisions on your extrude will give you more smoothness, but unless it's very large I don't think you should need too many. Depending on your package, you may be able to smooth and maintain hard edges at the end as well.

kiri: Interesting to see your method. Looks good, but I think my method might achieve results slightly more accurate to the wikipedia reference. Went a lot faster now that I knew where I was going to have problems. I'd say 10 minutes as well, with some time taken out to figure out how to take decent screenshots and post em :p .

synergy11
03-02-2007, 06:09 PM
The only thing I can find close to the lathe operation is the revolution around axis or curve..this is what I get..looks cool but I can't figure out how to join these 4 pieces...

oh i just noticed glib's repost..going to try that one now.

I find both the methods look great. There actually both different kinds of vaulting. I would use both of them in my designs.

glib
03-02-2007, 06:47 PM
Syn: For a different arch, take what you just posted, merge the 4 pairs of verts that are touching, then grab the 4 interior ones and simply scale them together and merge. Might be a cool look.

synergy11
03-02-2007, 06:58 PM
Thanks glib...i'll try that out..

I had a question on your tutorial though..how did you get from picture 4 to 5? Why did you lose your thickness in the arch?? What cuts did you make..i tried cutting but i got a huge mess. is there a way you can illustrate your steps there..sorry for bothering : )

synergy11
03-02-2007, 07:10 PM
Not sure how to merge verts in XSI..there's a merge command under "Create Polygon mesh":"Merge"

That seems to make my four models become selectable as one....then I took those 4 verts and scaled them close together so there on top of one another..then merged again..looks good but there seems be some distortion going on..like some hidden edges were added that I can't select...Might be nothing.

THanks again!

glib
03-02-2007, 07:14 PM
It's hard to illustrate without a video, as I can't take a screenshot while I'm in the middle of a cut.

I'll try to explain though. Get into a side or front view to rid yourself of perspective distortion. Use the form of one arch as a something to trace to get the shape right, thats the only purpose it serves. Trace out the top line of the arch as it intersects your other one. It should come right to the top, and then down to one of the sides although possibly not all the way to the bottom (depending on which one you're looking at).

I deleted the thickness to avoid the hassle of having to trace the same outline on the underside, as the edges don't match up well and it would have been quite a pain (this is what I struggled with the first time, so I learned my lesson the second time around). It's far easier to get the shape as a surface first, then extrude to give depth at the end.

Here's a pic from the side view, the red is where you cut, and you're cutting the arch we're seeing from the side (the one that looks like a rectangle in this view, not the one that looks like an actual arch).
http://www3.telus.net/public/liamg/step4a.png

glib
03-02-2007, 07:46 PM
Not sure how to merge verts in XSI..there's a merge command under "Create Polygon mesh":"Merge"

That seems to make my four models become selectable as one....then I took those 4 verts and scaled them close together so there on top of one another..then merged again..looks good but there seems be some distortion going on..like some hidden edges were added that I can't select...Might be nothing.

THanks again!
I use XSI at school, but only for animation not modelling, and I don't have it at home to open for reference. I believe what I refer to as combining it calls merging. What I call merging verts, it calls welding verts.

kirigoi
03-03-2007, 01:18 AM
Synergy, that looks like the right operation, but you've done it with what looks like 12 turns around the axis. There should be an option to change this value. You need to set it to 4, then it'll work.

Glib, any method that produces the results you want could be described as a correct method as it gets the job done, however I frankly wouldn't do it the way you've described. There's a lot of work even when you've only got 12 spans on your curve, and that would only be multiplied with a complicated arch profile or a curve with hundreds of points (all of which would need to be cut, positioned and merged by hand).

And I'm not sure what you mean by saying your method would be "more accurate to the wikipedia reference". If you mean that I haven't made a model with a roof, that's true, but I was going by the photos of real groin vaults where they are supporting loads. It's not hard to change what I had into the following either by extruding out the faces of the arch, or changing the profile of the original cross-section to give the arch thickness:

http://www.skylight3d.com/images/CGTalk/screens/groin_vault_08.png


Perfect 90 degree angles, a perfectly smooth curve without having to cut and merge dozens of vertices... How is this not accurate? ;)

Anyway, I don't mean to criticise; your first post on CGTalk was to offer someone help after all, but I'd be interested in hearing why you think this way is worse.

glib
03-03-2007, 06:12 AM
:) I know when I'm beat: you're right, your method is far easier and achieves the same result, I just wasn't seeing it before.

synergy11
03-03-2007, 04:52 PM
Hey kirigoi, thanks for posting.

In XSI when I do the Create Polygon Mesh: Extrusion Along an Axis...the minimum revolutions I get is what was posted on my last picture post. I can ad more sides but not less... hrm.


Maybe I should purchase lightwave lol.

Also I'm not sure how you altered your original tutorial to get the last post you posted ..it looks awesome. Would you be able to show in more detail how you got that result?

These tutorials should be posted somewhere permanent. I searched high and low on the net for these types of Architectural Tutorials...

This forum is great.
Your time is appreciated

glib
03-03-2007, 05:18 PM
Yeah kiri, I took a stab at your method, and while I can reproduce what you originally showed, I can't get to your last update without a bunch of ugly manual hacks.

syn: I don't have xsi in front of me, but like most things in that program, even if dragging the slider doesn't gave you the value you want, you can always type another one in. Try just manually entering 4.

synergy11
03-03-2007, 08:10 PM
I did : (

It could be I'm using the wrong tool.

kirigoi
03-03-2007, 10:41 PM
You're using the right tool synergy. In the dialog there should be a section with Subdivision options with U and V values. First set Subdivision Type to Absolute rather than the default of "Per Span", as this is most likely your problem. You can then set U=4 to get the results I posted.

You're absolutely right Glib, it's a little more involved to get to that last picture. I'll put together another few images in a bit to show one way of doing it.

You're right about the problems of keeping track of tutorials Synergy. There's some great sites that keep user-submitted lists of tutorials e.g. this one (http://members.shaw.ca/lightwavetutorials%20/Main_Menu.htm) for Lightwave, but they're not ideal as sites often change and the tutorials disappear. I've done a lot of these kind of examples on CGTalk, I should probably put them on my website as they are likely to slowly disappear into the archives, but hardly anyone's going to find them there. The beauty of CGTalk is that there's almost always someone who can help you out if you get stuck and can't find a tutorial (I know I've been helped no end over the years).

puzzledpaul
03-04-2007, 12:34 PM
This is a wings specific set of tuts for making pipejoints, but the approach is still a valid one and could presumably be adapted to other apps / toolsets.

The particular strip being referred to is the 2nd from the beginning - Making a 4 way joint, and this is based on the geom associated with a default (16 sides in wgs) sphere.

If the individual arch cross-sections (viewed/projected along xz) aren't to be semicircular, then the crucial pic (imo) is the 2nd from left ... no need to do the rest.

Extruding the (regions of) faces bounded by the selected edges along x,z will give the basic (solid) shape that just needs 'hollowing' by whatever method is available (a single Face | Intrude command in wgs)

Scaling > Y the whole structure will obviously alter the arch shape / height (with 70.71% needed to regain a semi-circular x-section)

pp



http://www.geocities.com/paulthepuzzles/aapipejoints.html

bandwidth meters are re-set every hr, on the hr - so if can't get in first time round, pl. bear this in mind :)

kirigoi
03-04-2007, 04:39 PM
Yep, that's another perfectly acceptable technique Paul, although be sure to set the scale to as close to √2 as possible, otherwise small errors will result (probably too small to matter for this kind of application though).

As long as we're collecting techniques, here's another similar one:

Create the arch cross-section you want
http://www.skylight3d.com/images/CGTalk/screens/groin_vault_3_01.png


Extrude it out
http://www.skylight3d.com/images/CGTalk/screens/groin_vault_3_02.png


Rotate the arch by 45°, and perform two cuts; one along the z-axis and one along the x-axis (make sure that they intersect perfectly at the origin by inserting exact numerical values for the cuts).
http://www.skylight3d.com/images/CGTalk/screens/groin_vault_3_03.png


Rotate the arch back, then extrude the selected polygons out along the appropriate axis (make sure you also select the triangle at the top). Flatten the end:
http://www.skylight3d.com/images/CGTalk/screens/groin_vault_3_04.png


Do the same for the other side and delete the end polygons. If necessary, force the extrusions to the same length using numerical inputs. Voila...
http://www.skylight3d.com/images/CGTalk/screens/groin_vault_3_05.png

glib
03-04-2007, 05:16 PM
:applause: That takes the cake kiri... simple, efficient, accurate. I like it. Thanks for sharing!

puzzledpaul
03-04-2007, 05:48 PM
<< although be sure to set the scale to as close to √2 as possible, otherwise small errors will result >>

Yep - for precision stuff I'd use other tools / approaches ... but the above is better than 0.001% of 'correct' fig ... and I've not come across too many UK builders who work to this sort of tolerance :)

... and this scaling factor is only required for the specific case of a (semi) circular cross section ...

pp

kirigoi
03-04-2007, 06:34 PM
You're not wrong there Paul... There's a gap under my kitchen door that's nearly an inch larger on the right than the left... :sad:

I only mentioned as it was intended to clone and join lots of these vaults, which is marginally trickier if they don't line up properly. There's some great tips on that page of yours though, I'll have to remember some of them.


Here's that tutorial I promised for making the full wiki-style vault using lathes:

1) Make a new profile, giving the arch some depth (you could also adapt the previous shape by smooth-scaling the arch out, but there's a few subtleties to doing it that way, so I'll start again from scratch):

http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_01.png


2) Lathe this with 4 sides:

http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_02.png


3) Seperate the column from the arch section, and place it in a second layer for later:

http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_03.png


4) You now need to split the arch part so as to only leave a quarter remaining, with closed ends at the cuts. There's plenty of ways to do this, e.g. create an object from a cube then perform a boolean subtraction. The two selected faces are on the x and z axes:

http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_07.png


or you could split the arches with a band-saw type tool, and create new geometry for the end caps by bridging edges. I don't want to spend too much space on this as the method will be largely dependent on the tools you have with your application, so click on the images if you want full-res pics:

http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_04_small.png (http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_04.png) http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_05_small.png (http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_05.png) http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_06_small.png (http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_06.png)

kirigoi
03-04-2007, 06:36 PM
5) You should now have the following:

http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_08.png


6) Make a note of the x and z coordinates of where the arches should end on the column, and move the end faces to these values.

http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_09.png


7) Create extra points on the inner parts of the column join where the red marks are and weld them to the green points on the edges of the column (you need to do this to ensure the mesh is closed).

http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_10.png


8) Create a polygon in the gap that's left using these four vertices:

http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_11.png


9) Move the model you have now away from the origin so that the selected faces lie on the x and z axes. You can now delete these faces.

http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_12.png


10) Mirror the geometry across the x and z axes:

http://www.skylight3d.com/images/CGTalk/screens/groin_vault_2_13.png


And you're done... The lathe method is more appropriate for cloning lots of vaults to create a large enclosed space, but it does work for this too.

glib
03-04-2007, 06:45 PM
Very nice. Mentioning booleans made me shudder a bit (I guess you're not using maya or max), but a band-saw style cut faces would work fine there.

It's funny, I've almost stopped using the revolve, lathe and loft tools that were my bread and butter in max since I moved to maya. They just don't work as well most of the time for me unfortunately.

By the way, that warhammer piece of your is coming along fantastically.

kirigoi
03-04-2007, 06:46 PM
... and this scaling factor is only required for the specific case of a (semi) circular cross section ...
Surely it's required for any type of cross-section, for the case where the extrusion comes out at right angles from the original mesh? Otherwise you get something like this (are we referring to the same scaling factor? ;)):

http://www.skylight3d.com/images/CGTalk/screens/groin_vault_09.png

kirigoi
03-04-2007, 07:05 PM
Mentioning booleans made me shudder a bit Yep, I very rarely use them myself, but this is pretty much a perfect example of when they are acceptable to use (in Lightwave at least) as the cutting geometry is very simple, and all the geometry to be cut is exactly perpendicular to the boolean object, so the math is pretty easy. I'm no boolean-nazi though; if it works I use it (it's getting the experience of knowing when it'll work that's tricky). I've even been known to use non-quads in subdivision surfaces *ducks*

By the way, that warhammer piece of your is coming along fantastically. Cheers matey! Hopefully it'll look pretty good when it's finished. Now I just need to stop bumming around on CGTalk and get on with it ;)

synergy11
03-04-2007, 07:31 PM
Thanks. I understand now how its done. It's just a matter of getting my XSI to only rev 4 times.

That other tutorial you just showed looks pretty easy. I imagine just extrude the faces down after to get some thickness?

Going to give it a try.

Thanks for the pic's.

puzzledpaul
03-04-2007, 08:23 PM
<< are we referring to the same scaling factor? >>

... probably not, but unsure (there's a 'politicians answer :) )

The original tut was for pipes, hence it was necessary to do a Rad scale op to regain the truly circular nature of the shapes defined by the 2 selected edgeloops (fig2) when viewed along either X or Z.

If creating an arch that wasn't circular - when viewed similarly - then there would be no need to do this 'circularisation' scale op.

At this stage you'd have a X(Z) projected shape where the width was 70.71% of the overall height ... scaling Y > at this stage would, of course, make the arch shape more 'squat' - or more 'peaky' (excuse the fancy techy terms, but in the process of sampling a bottle of Grants:) )

I'd also be tempted to suggest NOT slicing the sphere in half earlier on, because loss of symmetry stops you using a single Extrude Normal op for all 4 selected faces in stages 5>6

Anyway, I think original Q asker has got a few options now...

Nice tech lego bike, btw ... still got some boxfuls in the loft somewhere ... great stuff :)

pp


Thx for comments re page - that's one of approx 40 odd ... all wings specific, so dunno how much use they'll be to others.

index page
www.puzzledpaul.com (http://www.puzzledpaul.com)

Sbowling
03-04-2007, 08:46 PM
Hello to all.

I have been having trouble with modelling a groin vault also known as a cross vault.
I searched high and low on the net and in forums for tutorials but none can be found.


As posted in the XSI section:

Something like this is about as basic as it gets in XSI. It shouldn't take you more than an couple minutes for a basic shape. http://www.ultrahypermeganet.com/groinvault.html (http://www.ultrahypermeganet.com/groinvault.html)

Sbowling
03-04-2007, 08:53 PM
5) You should now have the following:

6) Make a note of the x and z coordinates of where the arches should end on the column, and move the end faces to these values.

7) Create extra points on the inner parts of the column join where the red marks are and weld them to the green points on the edges of the column (you need to do this to ensure the mesh is closed).

8) Create a polygon in the gap that's left using these four vertices:

9) Move the model you have now away from the origin so that the selected faces lie on the x and z axes. You can now delete these faces.

10) Mirror the geometry across the x and z axes:

And you're done... The lathe method is more appropriate for cloning lots of vaults to create a large enclosed space, but it does work for this too.

:eek: I'm so glad I don't use lightwave anymore.

kirigoi
03-04-2007, 10:55 PM
:eek: I'm so glad I don't use lightwave anymore.

Cheers Sbowling, ironically, I was trying to keep things overly simple and application non-specific so that even a lowly XSI user would be able to understand... :p

There's no point me including a bunch of Lightwave specific tools when the tutorial wasn't intended for a Lightwave user. The tutorial was for a more complicated model than the one you showed (which incidentally used a very similar method to a Lightwave one already listed in this thread).

There's plenty to bash Lightwave about, but for little poly-models like this it's about as fast as you can get.

Sbowling
03-05-2007, 12:13 AM
Cheers Sbowling, ironically, I was trying to keep things overly simple and application non-specific so that even a lowly XSI user would be able to understand... :p

There's no point me including a bunch of Lightwave specific tools when the tutorial wasn't intended for a Lightwave user. The tutorial was for a more complicated model than the one you showed (which incidentally used a very similar method to a Lightwave one already listed in this thread).

There's plenty to bash Lightwave about, but for little poly-models like this it's about as fast as you can get.

I was actually commenting on the numbe of steps it took to get your results. There really isn't that much difference in the complexity of that model V.S the one I made. The only real difference is that you've added some thickness (duplicate and scale the initial curve) and placed a couple cubes at the corners of the arches. The biggest problem with the method you showed is that the profile of the arches will be wrong, since you have to rotate everything 45 degrees.

I would definitely disagree with you on that last part. :)

Edit: The original poster was asking about doing this in XSI.

kirigoi
03-05-2007, 02:34 AM
The biggest problem with the method you showed is that the profile of the arches will be wrong, since you have to rotate everything 45 degrees.I refer you to my original post (http://forums.cgsociety.org/showthread.php?p=4230892#post4230892):
This profile represents the shape of the diagonal arris, so you will need to make it wider than you expect (or you can model the profile of the arch then multiply it horizontally by a factor of √2)
Sure that way I showed was inefficient. I could have skipped half the steps in that tutorial or used more efficient methods, but when I did that before I was asked for more detail. I also showed another, more efficient way of doing it (one that was at least as efficient as the one you linked to). Someone asked me how I could adapt the first method I posted (hence not just scaling the arch and adding cubes) to create a specific model from a wikipedia site, and I showed them in detail. I even said it wasn't the best method:

The lathe method is more appropriate for cloning lots of vaults to create a large enclosed space, but it does work for this too.

I would definitely disagree with you on that last part. :) I've had a good go with most (admittedly not all) of the software packages out there, and all have a basic modelling set that can make a cross-vault shape with only a few mouse clicks. How is XSI better when it needs the same number of steps to make it? Make a curve, extrude, cut(x2), extrude and you're done. In Lightwave just as in XSI. Sure, XSI's advantages become massive when you start anything more complicated, but unless Softimage have come up with a way to make a curve without touching any controls at all, this simple stuff is limited by our need to instruct the software package what to do.

If you disagree so strongly, feel free to show how to produce the results of my original post (http://forums.cgsociety.org/showthread.php?p=4230892#post4230892) using XSI. If you can do it in fewer steps than I showed (please translate "make note of x, move by x etc." to move with grid-snap), I'll happily concede that XSI is better for this application.

M

EDIT:
Edit: The original poster was asking about doing this in XSI.True, but this is in the general modelling forum, and Synergy said "I'm using XSI but if someone can explain it in their program I'll try to figure it out." which doesn't sound like he was ruling out submissions from other software users. I even helped him with an XSI specific query ;)

Sbowling
03-05-2007, 06:19 AM
I refer you to my original post (http://forums.cgsociety.org/showthread.php?p=4230892#post4230892):
If you disagree so strongly, feel free to show how to produce the results of my original post (http://forums.cgsociety.org/showthread.php?p=4230892#post4230892) using XSI. If you can do it in fewer steps than I showed (please translate "make note of x, move by x etc." to move with grid-snap), I'll happily concede that XSI is better for this application.

The main advantages with XSI in this kind of simple modeling is that I don't need to take note of any coordinates. XSI allows me to move centers and and snap to grids (or anything else for that matter) without even thinking about it. From what I remember, this isn't as intuitive or even possible (as far as snapping goes) without some expensive 3rd party tools.

Anyway, here's another video of something similar to what you made. Took about 5 minutes to make (It's all real time in the video) and several hours to get the video into a suitable size for upload. I don't think the way I made the first quarter of the arch (right after the extrude) Would really be that useful if you are working to a specific scale, but I was just looking at a different way to do things.

Here's the link:
http://www.ultrahypermeganet.com/groinvault.html

Edit:Forgot about LightWave not having any tool handles, or manipulators, or whatever you call them for scaling, rotating, etc. in modeler. Ugh!

Also, Cool image of the Lego motorcycle. Takes me back to when I was a kid with my legos. I can't seem to find those big expert builder kits anymore and I wanted to buy some for my nephew.

kirigoi
03-05-2007, 01:34 PM
The main advantages with XSI in this kind of simple modeling is that I don't need to take note of any coordinates.True enough... Vanilla Lightwave is woeful in that regard. Fortunately, I upgraded to Lightwave v9 before it was released, so got a free copy of LWCAD thrown in, which has some excellent snapping tools. It's still available bundled with Lightwave for a fairly reasonable fee.

You wouldn't catch me actually making physical notes of coordinates(!), but I was trying to keep my tutorial very general as it is in the general modelling section. For software packages with grid-snap it's the obvious solution, otherwise you've got to do it numerically.

Edit:Forgot about LightWave not having any tool handles, or manipulators, or whatever you call them for scaling, rotating, etc. in modeler. Ugh!
I think this one comes down to personal preference; half the time I appreciate the handles when I'm using Maya, other times they just get in the way and slow me down. The clean workspace in Lightwave Modeller appears to be a design decision (they're there in Layout), and I think I personally prefer it, although it does constrain you more to using the default quad-view as each view acts as a handle for that plane. That said, I would prefer the option.

My biggest gripes with modeller are that I miss being able to easily set action centres to specific points, and have tools operate on different planes than xyz, but there's usually a way round it (and a free plugin for the latter).

If you want to see how I would personally model in Lightwave, here's a version of the method you used. It's entirely applicable to LW, although I did an extra step to extrude the bottom of the arch down, as Lightwave's Rounder tool (like the bevel you added) often doesn't play nice on vertices where the edge loop terminates.

http://www.skylight3d.com/images/CGTalk/video/LW_groin_vault_screen.jpg (http://www.skylight3d.com/images/CGTalk/video/LW_groin_vault.avi)

1m22 AVI file: 1022x788 1.39MB using Techsmith Screen Capture Codec.


And here's a video showing how to use cloned lathes to create a huge groin-vault hall like in my first post (plenty of Lightwave snapping in this one):

http://www.skylight3d.com/images/CGTalk/video/LW_groin_vault_lathe_screen.png (http://www.skylight3d.com/images/CGTalk/video/LW_groin_vault_lathe.avi)

1:15 AVI file: 1016x800 2.21MB


Both are real-time, although I started with a completed arch profile for the second one as modelling the arch profile is rather trivial. Unfortunately, I don't think these are so useful for tutorial purposes as I use a lot of keyboard shortcuts, which can't be seen on the video. Hence the overly simplified tutorials above ;)


I don't know, perhaps I'm just suffering from Lightwaver's Spleen from too many digs at what I reckon is a fairly competent modelling package (although very short on bells and whistles). As far as my limited experience tells me, modelling skill is almost entirely independent of the application you use. Far too many people on CGTalk seem to think that all you need to do is get hold of the latest version of Maya or XSI and suddenly you'll become an amazing modeller, when really you can pick up the skills with pretty much any of the packages on the market. That said, aiming to be as employable as possible is an appropriate reason to spend time on a particular package when you're a beginner, but by that logic everyone should learn Max and Maya... :shrug:


Also, Cool image of the Lego motorcycle. Takes me back to when I was a kid with my legos. I can't seem to find those big expert builder kits anymore and I wanted to buy some for my nephew.Cheers matey, I was pretty glad how it turned out too, although my new Warhammer model is gonna kick its bum. It was nice getting my old lego down from the attic to do it. If you're looking for the big kits eBay seems a good choice; there's usually dozens of them going for fairly reasonable money (at least in the UK).

synergy11
03-06-2007, 05:18 PM
Well I got this far..

SBOWLING:
I was just wondering how you would add depth to this model? Like on the wikipedia page or in earlier posts.

I tried duplicating edges and scaling in..tried extruding polygons. Unless I'm doing it wrong I can't seem to figure it out.

Thanks for the great posts and videos. It really makes a difference when you "see" it done.

It would be great if you made a video showing how to get the hallway arches like in kirigoi's 2nd vid but in XSI. :)

You should make a website and charge for custom video tutorials. I would subscribe!

Any help appreciated.
Thanks again.

synergy11
03-07-2007, 01:03 AM
Nevermind I re-read the posts and know how to do it now.
I will post my finished models when done.

Thanks again!

Sbowling
03-09-2007, 08:44 PM
Well I got this far..

SBOWLING:
I was just wondering how you would add depth to this model? Like on the wikipedia page or in earlier posts.


I saw in your other post that you've got the problem worked out, but someone just posted a script fro adding thicknes to models which may also come in handy. http://www.xsibase.com/forum/index.php?board=29;action=display;threadid=29317;start=0#msg191541

Sbowling
03-09-2007, 10:13 PM
True enough... Vanilla Lightwave is woeful in that regard. Fortunately, I upgraded to Lightwave v9 before it was released, so got a free copy of LWCAD thrown in, which has some excellent snapping tools. It's still available bundled with Lightwave for a fairly reasonable fee.

LWcad has some interesting features, but it wasn't available at the time I finally gave up on LW. I was wondering what a "reasonable fee" was, but I don't see it one the newtek website. I did get a good laugh at the LW9.2 fluff piece on the front page. Apparently a "Pipeline" is a new concept to Dave Gerrard. No disrespect intended, I know he is talented and I know he knows what a pipeline is and why studios use them. Having your best lighting guy working on modeling or animation would just be dumb. :)

[quote]
I think this one comes down to personal preference; half the time I appreciate the handles when I'm using Maya, other times they just get in the way and slow me down. The clean workspace in Lightwave Modeler appears to be a design decision (they're there in Layout), and I think I personally prefer it, although it does constrain you more to using the default quad-view as each view acts as a handle for that plane. That said, I would prefer the option.

Actually, the great thing about XSI is that you can turn these off in XSI and only use them when you need them. I prefer them on most of the time, because they are extremely handy when you need to move polygons, etc along a normal, in local space or global space.

As for lightwave not having them, I would guess it's much the same reason lightwave had different versions of OpenGL between modeler and layout, the same reason why half the recent features are 3rd party and why CA sucks big time in LW.:shrug:

My biggest gripes with modeler are that I miss being able to easily set action centres to specific points, and have tools operate on different planes than xyz, but there's usually a way round it (and a free plugin for the latter).

Again, another great thing about XSI is that the need of these free (and many times not free) plugins is almost nonexistent in XSI. My plugin list includes, a volume shader plugin, a hair plugin, and the XSI version of the IFW textures.



If you want to see how I would personally model in Lightwave, here's a version of the method you used. It's entirely applicable to LW, although I did an extra step to extrude the bottom of the arch down, as Lightwave's Rounder tool (like the bevel you added) often doesn't play nice on vertices where the edge loop terminates.<munch images>




And here's a video showing how to use cloned lathes to create a huge groin-vault hall like in my first post (plenty of Lightwave snapping in this one):

You mean LWCAD snapping. :) In fact, through most of the videos you seem to rely heavily on LWCAD.











I don't know, perhaps I'm just suffering from Lightwaver's Spleen from too many digs at what I reckon is a fairly competent modelling package (although very short on bells and whistles).

I was an avid LW supporter for a long time, but it's day is done. It's modeling features are extremely dated and it has an overwhelming number of nearly identical features that should really be streamlined and integrated into a single feature. Most of the new features are 3rd party plugins and the entire user interface it extremely inflexible and not very friendly.

This doesn't even cover the mess that is the lightwave directory system. I jump between work and home constantly when working and need to be able to easily move all the required parts of a project between work and home. In lightwave this is a mess and I was always having to go back to get an image, or a model that I forgot to bring with me. In XSI I just grab the project directory (that XSI sets up for me) and burn it to a CD and I'm done.

The only real interest Newtek seem to show in improving LW is the rendering side. I would guess that's because Lightwave is largely used as a cheap render solution in many studios with the real work being done in other packages. The Scion commercials are a great example of that. I kept hearing they were done in lightwave, but finally found out that they were animated in XSI and only rendered in Lightwave.

I also notice that you refer to Maya a lot. I haven't spent a lot of time with Maya, but I know a lot of people are less than enthusiastic about Maya's modeling workflow. I'd be interested in seeing your impressions of XSI after spending some real time working with it (more than an hour or two).


As far as my limited experience tells me, modeling skill is almost entirely independent of the application you use. Far too many people on CGTalk seem to think that all you need to do is get hold of the latest version of Maya or XSI and suddenly you'll become an amazing modeler, when really you can pick up the skills with pretty much any of the packages on the market. That said, aiming to be as employable as possible is an appropriate reason to spend time on a particular package when you're a beginner, but by that logic everyone should learn Max and Maya... :shrug:


User ability is always important, but either I magically became a much better modeler the instant I switched to XSI or it's interface and workflow have helped me work to the full level of my abilities. In lightwave I was always held back by the limitations of the program for modeling and animating, now that I'm in XSI I find the only thing holding me back is my own ability. It does kill off a lot of my excuses when things are late though. :sad:

[quote]
Cheers matey, I was pretty glad how it turned out too, although my new Warhammer model is gonna kick its bum. It was nice getting my old lego down from the attic to do it. If you're looking for the big kits eBay seems a good choice; there's usually dozens of them going for fairly reasonable money (at least in the UK).




My biggest worry about buying something like legos off of ebay is that they might be missing pieces. Actualy, I just found the Technic models, not nearly as nice as the Expert builder sets IMO, but I think they will still be fun and challenging for my nephiew. If he really likes it I'll buy him the battery powered motor (I always wanted that when I was a kid, but we were too poor to buy it).

synergy11
03-10-2007, 11:47 PM
Here is what I got.

Some weird visual anomolies when I render it? Maybe the original profile wasn't perfectly straight?

I also used the capping method
http://edharriss.com/tutorials/tutorial_xsi_cap_holes/Cap%20Holes/How%20to%20cap%20holes%20in%20Softimage%20XSI.htm

to close of the sides after I cut it up with the knife tool. It worked but now it seems like I cannot select the polygon it made (the cap).

I am also wondering how you align things to the axis in XSI? I tried holding shift down but it wouldn't snap to the grid I wanted.

After I cut it up; to get the other 3 sides I symetrized mesh.

Thanks for all the help.


EDIT: the triangle count for this model is 3232

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