View Full Version : Experienced Help Needed.

03 March 2007, 10:50 PM
Hello, I am trying to model this sphere with arches going around it..however running into many problems.

The approach I took was to create one of the bottom segments with curves then use a curves to mesh with no extrude.. then I duplicated edges to bring out the arch. Then I duplicated around the sphere and merged.

However when I do a render test theres some hardness going on that does not look good.

Is there a better way to approach modeling somethings like this. Or is there a way I can fix the hard edges.


03 March 2007, 12:20 AM
Firstly... can we see the wireframe? Without seeing your topology, it's near impossible to see exactly what's going wrong here.

Second... please keep your posts on this model contained to one thread. There have been at least 3 threads on this model. I will be merging them when I get a moment.

Third... although I cannot see your wireframe topology... I am experienced, so I can imagine exactly what it looks like. It looks as if you are lacking a great deal of understanding of proper topology knowledge. It's understandable, as you are likely new to the process. I recommend doing a handful of the 1000's of modeling tutorials available for free on the web, or if you would like to expedite the process, there are several producers of high quality commercial tutorials that can help explain how topology, meshflow and general polygon modeling works.

Post your wireframe, and I will try to make some time to illustrate what you are doing wrong.

03 March 2007, 01:23 AM
Try this -

hit the + key (on numpad) to smooth your model.. You'll probably notice that it rounds it out too much. Select the edges around the arches, and mark them as hard (or use edge crease).

To see how that works, maybe try it with a cylinder first. You don't want all the edges to be hard, only the ones around the rim.

03 March 2007, 01:25 AM
Jdex - aren't those arches that he wants different than the other threads (groin arch)?

03 March 2007, 02:30 AM
I looked... yeah, there's 5 or 6 threads on different types of arches... a couple are on dome like arches, but they are at least different. I won't merge them, but I think that we now could have a damn good unified "Modeling Arches" thread going. ;)

03 March 2007, 07:49 AM
This method may work... create the arch as an object you can boolean the sphere with. (ie the arch shape that is extruded) Once the sphere is cut out, duplicate and scale the arch down, and boolean the original arch with it to make it hollow... Then create a slightly larger sphere and do a boolean interect on the arch...

Hope that makes sense.


03 March 2007, 11:23 PM
Hello and thanks for replying.

Here is the wireframe image.

I have done as many tutorials on the web as I can find. Most are for organic modeling unfortunately.

I also have bought all the XSI tutorials I can find including the ones from ( and ( Which both were very helpful, none of them really tackled the models or architecture I'm trying to make (ie. groin vaults, rib vaults, arches that are curved and attached to spheres : ). I am currently going through the DVD's from Noesis Interactive.

If there are any other commercial tutorials out there please post!

Thanks for your help. These forums have been super helpful.

To dwigfor: I've tried that process with no luck.

And to the boolean poster..I'm pretty sure I want to stay away from boolean unless It can't be done otherwise.

03 March 2007, 02:40 AM
Hello and thanks for replying.

Here is the wireframe image.

If you can post a link to a picture of what you are trying to create (like you did before) I will try to help out. I'm not exactly sure what type of look you are going for, so I can't really help much.

03 March 2007, 05:28 AM
In one of the other threads, there was a link to the "Minus Terith (sp) Project" It had about a 50 page pdf making of which I think you'll be interested in.

Adding more edges would smooth out you mesh. Try keeping everything 4 point polys.

03 March 2007, 05:24 PM
If you're refering to the 39 page pdf document on the minas tirith home page..ya I checked that out. It had great info in it. The only thing I could not mimic in XSI out of that doc was the Bend deformer they applied to get the bent arch look. Any ideas??

for Sbowling: Here are some more pics of the look im going for

1st Pic: Kinda like this but from the outside and less detail. See how the arches go around the sphere and they are curved?

2nd pic: These arches are curved too but only one way. Not sure how to do that either.

I'll try adding more edges to my example above and see if that smoothes it out. It looks fine in the wireframe but not in can see the hard lines.

A lot of the buidlings done for the minis tirith have similar things I am trying to accomplish in XSI. Here is a link

See the building closest to the camera in the front? The bottom segment has arches that curve around the tower.

03 March 2007, 11:27 AM
To get this working you have to build your mesh different. Start with what ever you want to model (sphere or cylinder a.e). Than Try creating the basic lines and cut out the polys you dont need. Use the skrink wrap deformer to warp your model on the starting model to keep it round.

Here is a little example:

03 March 2007, 09:54 PM
Is there any way you can post a more detailed tutorial for this newb? Especially the shrink wrap deformer part.

Thanks for the pic.

I'm going to try the cutting method right now.

Again any help is appreciated.

04 April 2007, 12:59 AM
Looking for some more help on this shape.

Here are my pics.

I'm trying to figure out how to keep the half sphere smooth as I cut arches into it.

Any help on keeping the topology "right" would be great!!


04 April 2007, 04:56 PM
Hi Synergy, I'm a bit busy at the moment, but I'll post a tutorial of how to replicate Helli's results at some point in the next few days. Like Helli, I'd definitely model this using Subdivision surfaces; you can always freeze it into polygons if needed. To be honest it shouldn't really be necessary as you should be able to copy Helli's topology fairly easily.


04 April 2007, 05:12 PM
sorry Synergy, double post, my internet access has gone a bit funny... I guess I owe you a tutorial now ;)

04 April 2007, 08:23 PM
That tutorial would be great kirigoi!

Thanks for the help.

05 May 2007, 02:37 PM
The tutorial is now posted here ( There was some confusion about where to put it as you've posted this question in so many places (See JDex's post).

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