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Sepheon
02-15-2008, 05:38 AM
Hello all.
I would like to say that im a maya user, but ive realized the many benefits of the XSI package, proportional modeler, ultimapper, etc, and i would like to start using it, first for rendering and as i get more comfortable with it for modeling and the rest. But Im having a problem here. The problem has 2 parts, first the problem, and the fact that im even having the problem is the next.

Problem:
I imported a model (.obj) into XSI, the normals are hardened. After searching "Soften Edges" on google for almost a half an hour i finally found XSIs stupid terminology "Mark hard edges". so i go to soften the mode, and i uncheck the box "Hard" and nothing happens, i close the box and open it again, its checked again. So obviously, the normals are locked, as happens most times when you export an obj. So i proceed to look up in the help and on google "lock/unlock normals, freeze/unfreeze normals" and nothing!!!

In maya, everything concerning normals is under the NORMALS tab. GO FIGURE HUH!?!

Sorry for the rant guys, so could anyone tell me how to unlock the normals of my model in xsi so i can render the thing?

curbsidebandit
02-15-2008, 06:33 AM
Iím not sure what you mean, but I assume you want your model to look softer and more organic, right? You can geometry approximate by selecting your object and hit the up/down arrow keys to dynamically smooth out the surface of your object, but obviously it makes the mesh heavier too. Whenever I model an organic shape I usually go up two levels for rendering.

"Mark hard edges" is for adding a crease to your mesh. For example if youíre modeling a head and you want to create a nice crisp eyelid, then you could select the edgeloop of the lid to make it sharp when you up rez the model.

If you just want to subdivide the model you can alt+right click and the option should be at the bottom of the list

Hope that helps you

Strang
02-15-2008, 06:49 AM
there is a 'user normal' property that might have gotten imported from maya. you should be able to delete that and let xsi do its own shading of the normals.

and btw if you know the benefits of xsi then we wont go into particulars when it comes to UI design and organization.

let us know if that works for you

mr-doOo
02-15-2008, 08:56 AM
In maya, everything concerning normals is under the NORMALS tab. GO FIGURE HUH!?!



having one more menu just for the 2 commands that are dealing with normals ??

Loolarge
02-15-2008, 09:26 AM
Not sure if this this is what you are looking for but i give it a go:

In the explorer double click on the "Geometry approximation" Propery
Go to the "Polygon Mesh" Tab
Under "Discontinuity" Play around with the "Angle" slider or turn "Automatic" on


I believe by default you set the normal angles of a mesh this way.

mdee
02-15-2008, 09:59 AM
In maya, everything concerning normals is under the NORMALS tab. GO FIGURE HUH!?!


Advice from long tima maya and XSI user (I sometimes alt tab between the two).

When in XSI stop thinking Maya.

Your original question was answered in other posts.

ThE_JacO
02-15-2008, 12:50 PM
In maya, everything concerning normals is under the NORMALS tab. GO FIGURE HUH!?!

yeah, that's amazing indeed.
Making edges hard however isn't just a normals thing so it shouldn't be in a normals menu (if there was such a thing in xsi anyway).

Making an edge a hard edge will affect subdivisions too, it does NOT split the normals.

As for your problem, chances are that you simply imported an obj with a cluster that defines custom normals, and being that a set of value they do what they are supposed to do, they override the underneath values regardless of how you set them.

Blast away the normals cluster and things will look more like what you expect.

Also if you keep thinking in terms of how maya groups and manages data (without going into why many people with a clue about design think maya had a lot of thought put into it, except it was by a spastic dog high on meth), you might find yourself frustrated all the time.

XSI is lacking in control over normals in general, but as a dataset it largely considers them derivative data, hence they are usually the consequence of setups and actions on other subcomponents, and not individually controlled (and in need of fixing every 2m) like you'll find them to be in some other apps.

In more generic terms the two apps have philosophies and views that are very, very distant in many regards.

Sepheon
02-16-2008, 05:34 PM
hello all!
many thanks for the replies.
I just wanted to mention that approximation was not what i was looking for.
You guys had it dead on when you mentioned the User_Normals attribute under Clusters in the explorer. What had happened was i checked a box in the import window that said "import normals as user normals" so i essentially caused this problem for myself!!
all i had to do was remove that tag in the explorer and it solved the problem! im such a noob XD

Thank you all for the info. Although jaco i do not agree with you about one thing. You are not "making edges hard" you are adjusting the normals connected to the face on that edge. it affects rendering and i believe that is all. When an edge is softened it just creates a gradient color/shade where the light hits those polygons, rather than a flat color/shade on the faces, making your model look smooth, even if low poly. I believe XSI softens normals by default.
Im not sure how XSI handles subdivision, but in Maya when i soften the normals of an entire model, then harden lets say 2 specific edges, when i Smooth(subdivide) the model those 2 edges act exactly like any other edge on the model, hardened or not.
I cannot imagine XSI subviding a model any differently, it just cuts each face into 4. Softening/Hardening normals(edges) is purely visual i believe.

mocaw
02-16-2008, 06:21 PM
Are you simply talking about adjusting the smoothing angle of the polygons? Sorry- a lot of people here have used Maya a lot more than I, so I guess I'm a bit confused when I try and translate that nomenclature to XSIs. Screen shots are worth a thousand words here- one of the model in Maya with any pertinent sub screens/windows and one of the model in XSI.

I guess the problem is solved- just translating everything so everyone is on the same page is left. I'm sure the Jaco will have some input for you- he likes a good fight over anything technical (he is after a TD {not just a lighting specialist}- correct?). I'm sure he works often or has on mixed Maya XSI pipelines as well.

So?

CiaranM
02-16-2008, 08:10 PM
Im not sure how XSI handles subdivision, but in Maya when i soften the normals of an entire model, then harden lets say 2 specific edges, when i Smooth(subdivide) the model those 2 edges act exactly like any other edge on the model, hardened or not.
I cannot imagine XSI subviding a model any differently, it just cuts each face into 4. Softening/Hardening normals(edges) is purely visual i believe.

Nope. In XSI when you apply a hard edge, it controls how the subdivision surface is generated across those edges. See in the attachment how the original normals (blue lines) are preserved. If you apply an edge crease value, you can control how sharp this edge is. Use intermediate values to lessen the sharpness. This is a very usefull modeling technique to add bevels etc. without the need to add extra geometry (just hit +,- to see the results). Even if you manually add local subdivision refinement - similar to Maya's Smooth command, the hard edges will be carried over to the subdivided mesh.
If you simply wish to adjust the normals of individual components of the mesh, there is a addon called UserNormalEditing that comes with XSI and can be found in the example SDK workgroup.

ThE_JacO
02-17-2008, 11:49 AM
Thank you all for the info. Although jaco i do not agree with you about one thing. You are not "making edges hard" you are adjusting the normals connected to the face on that edge. it
affects rendering and i believe that is all.

I wasn't guessing at the difference, mine was a fairly matteroffact statement :) It is a relatively moot point though, and I was just explaining why I said putting the command under a normals menu would be inappropriate.

As posted above try to adjust the smoothing level of a mesh with hard edges and you'll see how it has a quality to it that isn't limited to normals.

To make edges hard just at normal level btw you can always split (disconnect components) edges. It's inconvenient in many regards to do so, but it's not incorrect or dangerous if you need to do it.

Sepheon
02-17-2008, 08:01 PM
ahhh thats very interesting Ciaran. I believe we have been speaking about different things and i must apologize for the misunderstanding. The harden edges that you mention seems to act like Zbrush's "crease edges". This is very different from what maya calls harden/soften edges.
If i am correct that XSI "Harden edges" adds an edge on either side of the edge you are "hardening" to get a crease. Atleast that is what Zbrush does. Maya has the same function under the Subdiv Surfaces menu called "Full-" or "Partial creases Edge/vertex"

Ive attached a picture of the effects of the Harden Soften edges i was looking for the equivelent of in XSI. So far XSI seems to soften all edge (Normals) by default. To harden an edge you need to select the edge and go to "mark hard edges" under the Modify -> Component Menu. Im willing to bet money that when you mark hard edges it will have no effect on the model when you Modify -> Poly. Mesh -> Subdivide Polygons. that is what i meant, by harden edges.
thanks for all the info guys. Ill be sure to use the correct terminology. now if i could only figure out how to render a normal map XD

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mocaw
02-17-2008, 08:13 PM
That's called smoothing angle/discontinuity angle in most apps I've used. As far as I know that is effecting how the normals are rendered.

Open up the Geo app ppg and set the slider to what you want. XSI defaults to 60 (which is more than most models need IMHO) if you want it hard you often need to go with an angle bellow 30.

Does Maya have so many odd names for things? I guess everything else I've used is odd since it has a larger market share...but...kind of makes it hard to search for a "universal" answer on the web for some things.

Hard and soft? Not the descriptive words I'd use...

McKertis
02-17-2008, 10:19 PM
The harden edges that you mention seems to act like Zbrush's "crease edges". This is very different from what maya calls harden/soften edges.
Its the same thing, its just that in XSI this harden/soften sorta have a double functionality. 2 for the price of 1. You can crease your subdivs with it, and you can edit your normals "hardness" with it.
Neat, huh ?

XSI defaults to 60 (which is more than most models need IMHO)
When working with low poly models - even 60 may not be enough, many times.

Anyway, returning to the original poster again - i totally understand you, i had the same question just the other week. Your (or rather XSI) problem is that XSI has the "Harden" menu item, but doesnt have a "Soften" menu item, whereas Maya have both available to you.

In XSI you should, as others said, go to the PPG tab of your model, and play with "Discontinuity Angle" parameter, and then "harden" anything specific you might want.
Harden works on subdivided models as well as on non-subdivided models.

ThE_JacO
02-17-2008, 11:20 PM
If i am correct that XSI "Harden edges" adds an edge on either side of the edge you are "hardening" to get a crease. Atleast that is what Zbrush does. Maya has the same function under the Subdiv Surfaces menu called "Full-" or "Partial creases Edge/vertex"
no, in XSI you can do that with a bevel to double up any edge selection, or with a duplicate to contour it with two more per edge (flow continuity being dependant on the quality of the selection, but usually being pretty cleverly done).
Those tools, unlike in Maya, are fully component modal.

Im willing to bet money that when you mark hard edges it will have no effect on the model when you Modify -> Poly. Mesh -> Subdivide Polygons. that is what i meant, by harden edges.
You just lost money.
Stop betting and double thinking, and just do it, and you will see that marking a hard edge DOES have an effect on the subdivided mesh, both in real time smoothing (proxy style) and when you decide to commit it to the topology.

marking a hard edge in XSI -IS NOT- just operating on normals, no matter how many times you second guess it, it's a factual thing you could check by just doing it on a mesh and then hitting + on the numpad.

As for xsi "smoothing all polys", no it doesn't. XSI does not work the way maya does, especially not with normals (which in maya are often in need of explicit handling several times during any building process)
XSI shades an unaltered mesh according to the discontinuity angle, that will determine, based on the ange between sample level (or point per poly if you want) normals whether they will be aligned (producing shading continuity) or not.
Hard edges will introduce another set of data to do derivative work by (a forced discontinuity at raw polys level, and an RR like creasing once meshes are subdivided), they are NOT however something that operates on normals directly, they only affect the way derivative data is generated at the lowest geometry approximation level (0 subdivisions)

Having explicit normal handling the way maya deals with it in xsi requires a cluster to override the derivated ones and the toolset present in the addon that was already mentioned (or other addons/tools).

Now stop trying to second guess every notion presented here and go play with tools and settings and things might start making more sense ;)

mocaw
02-18-2008, 12:10 AM
Since we're on this topic...about normals and such...one thing you might notice is that if you scale a model and distort it in any axis the shading gets a little messed up, esp in the viewport. To me it looks as if XSI is referencing the pre-distorted geometry before shading it in the view port. If you freeze the scaling (not the model) you'll get your shading back the way it was.

OK, now ask 40 questions about it and how it's different in XYZ application...

Sepheon
02-18-2008, 04:19 PM
i hate to argue with you Jaco but I did try it.
I select half the edges on my model, went to Component -> mark hard edges. They are now hard. then i went to Poly mesh -> subdivide polygons. It simple splits each face into 4. There is no change between the faces that were Marked Hard and the ones that were not.
Are you perhaps talking about a subdivision surface such as the sphere in CiaranM's Picture? im not quite sure how to convert my mesh to a Subdivion surface in XSI, but regarding subdividing polygons in regular polygon mode using the Poly Mesh -> Subdivide Polygons function i believe i am correct in my assumptions. have you used this function on a polygon mesh recently?

Stop betting and double thinking, and just do it, and you will see that marking a hard edge DOES have an effect on the subdivided mesh, both in real time smoothing (proxy style) and when you decide to commit it to the topology.
just to clarify... A Subdivided Mesh and a Subdivision surface(Proxy) are two seperate things.
A Subdivided mesh is just a polygon that has been Subdivided 1face=4=16=64=etc, it is still a polygon mesh!!

the mesh in Ciarans pic is not a polygon mesh, it is a "Subdivision Surface" (Nurbs/poly hybrid) mesh or what some may call a proxy. I dont mean to step on anyones toes but When dealing with a basic polygon mesh, i do not seem to be wrong.

I have no doubt that when your model is in "Proxy mode" marking hard edges on your model has some effect. I only meant when it was a standard polygon it does not have an effect when you subdivide the mesh (NOT TURNING INTO A PROXY).

also, As for xsi "smoothing all polys", no it doesn't. XSI does not work the way maya does, especially not with normals (which in maya are often in need of explicit handling several times during any building process)
Maya does not smooth all polys either. BUT, when i select the "shaded" option from the viewport menu all models show with softened edges (smoothing angle). This is correct is it not?
I have yet to see a model show up with any other smoothing angle when i switch to shaded mode.

please try these two things before anyone flames me. And please also keep in mind that i have not converted my model to a subdivision surface, proxy, or approximation. thanks

ThE_JacO
02-18-2008, 07:19 PM
i hate to argue with you Jaco but I did try it.
I select half the edges on my model, went to Component -> mark hard edges. They are now hard. then i went to Poly mesh -> subdivide polygons. It simple splits each face into 4. There is no change between the faces that were Marked Hard and the ones that were not.
because all you did was just adding splits there. How that would be pertinent to a discussion about hard edges being "limited to normals" beats me :)
try hitting + and - on the numpad and marvel at what geometry approximation will gift you (and go remove the 1, 2, and 3 keys from your maya keyboard in rage ;) )


Are you perhaps talking about a subdivision surface such as the sphere in CiaranM's Picture? im not quite sure how to convert my mesh to a Subdivion surface in XSI, but regarding subdividing polygons in regular polygon mode using the Poly Mesh -> Subdivide Polygons function i believe i am correct in my assumptions. have you used this function on a polygon mesh recently?
subdivide polygon is basically a split, and it doesn't alter the shape of your mesh in any way, but since we were talking about smoothing, discontinuity, normals etc I thought you meant local subdivision refinement (a subD like split).


the mesh in Ciarans pic is not a polygon mesh, it is a "Subdivision Surface" (Nurbs/poly hybrid) mesh or what some may call a proxy. I dont mean to step on anyones toes but When dealing with a basic polygon mesh, i do not seem to be wrong.
the mesh in Ciarans pic is still a polygon mesh in xsi, it's simply being given a higher geometry approximation.
I'll have to copy the long version of "this isn't maya" phrases in a few flavors and start randomly pasting it into my posts in this thread I guess.

I have no doubt that when your model is in "Proxy mode" marking hard edges on your model has some effect. I only meant when it was a standard polygon it does not have an effect when you subdivide the mesh (NOT TURNING INTO A PROXY).
XSI -does not- turn things into a proxy, it's one of many things people have been trying to get across.
The phenomenally retarded design approach of having to duplicate data to derivate something out of it (smoothing, ik etc) thankfully never made it to XSI.

And again, when the mesh is in "standard polygon" make edges hard still isn't a "normal operation that should be in the normals menu". That was your original point and what I'm trying to correct. How dividing polys linearly reveals itself (unsurprisingly) unaffected by a hard edge has got anything to do with the matter at hand beats me and hangs me out to dry on a warm day.
Chances are you're still thinking in maya terms if you think that subdivide polygons should do any bloody thing with a hard edge :p

It adds data to a mesh that's got absolutely bugger-all to do with normals. The derivative approach xsi has by default with normals simply happens to consider that data.
The main purpose of hard edges (which are nothing but a crease kept at top value to have a shard edge regardless of dicing) however is largely tied to subdivision surfaces related things, and it's usually not a smart way to approach operations that you really mean to explicitly affect normals.

also, Maya does not smooth all polys either. BUT, when i select the "shaded" option from the viewport menu all models show with softened edges (smoothing angle). This is correct is it not?
I have yet to see a model show up with any other smoothing angle when i switch to shaded mode.
I didn't say that maya sets everything to smooth, I said maya handles normals explicitly all the time, whereas xsi has a different approach by default.
As for seeing a model not being smooth shaded, have you tryied a cube? The angle between a cube's normals is always over 60 degrees, and that's why it's not smoothed.

XSI has a parameter called angle under the discontinuity group, in the polymesh tab in the geo approx property. That determines when things will get smoothed out or not. Above that angle value normals will be left untouched and show discontinuities.

That is very different from "smoothing all", or the equivalent of selecting all normals in maya and running a merger.


please try these two things before anyone flames me. And please also keep in mind that i have not converted my model to a subdivision surface, proxy, or approximation. thanks
Please try to convert one to it then.
You keep doing what you've done in every post, which is double guessing and arguing every notion or piece of advice put forward, when all everybody's been telling you really is "XSI is different from Maya, stop thinking in those terms because you're pretty much getting everything wrong". I still have to see a single "flame" to be honest, it's just very, very hard to have any intelligent exchange when you're clicking maya's menus in a different app and insisting that you've "got it" because they don't do what they should do in such other app.

Good luck.

sacslacker
02-18-2008, 07:35 PM
The problem with the "forget how Maya works" argument is that some of us HAVE to work between the two now and it does get a little confusing for those of use who are trying to get to the same level in XSI as we are with Maya. Sure, moving lock stock and barrel to XSI would be cool but some of us (at least I) can't to that yet. Luckily XSI makes it pretty easy to get back and forth between the two. When it comes down to it, normals are normals whether or not XSI handles them more elegently or not. When you talk specifically about normals, there's not much difference. However, I'd agree XSI really got it right in the way they handle subdivisions and modeling in general. No point in arguing that.

Anyway, this thread helped me a lot too! Thanks!

Sepheon
02-18-2008, 09:09 PM
I bow down to your infinite xsi wisdom jaco.
although u've been kind of a dick about it, i have learned alot and i would like to thank you.

ThE_JacO
02-18-2008, 09:22 PM
I'd never say "forget how something else work", and I've used several apps and delivered shots for several movies with 4 different apps and three different rendering engines in the last ten years or so.

I also wouldn't want to be appearing exceedingly aggressive in my replies (despite my increasing efforts to use smileys in posts), when my intent isn't to belittle or flame anybody.

There are however two ways of migrating knowledge to different fields that somehow exist in the same context of a familiar one.

One way to do it is working hard to understand the essence of the underlying mechanics in different softwares, and how different design and implementation philosophies will reflect those mechanics and offer different degrees of fruibility and accesibility.
That is best done trying to understand what you're doing rather then how you do it, and abstracting form from substance.

Another way to do it is assuming all things work the same way (when they really don't, they just share SOME common principles) and painstakingly building in your head a lookup table , which will inevitably contain holes where things don't map, of one app as a layer of another.

The former requires method, effort and a will to try and revisit the way you think of some things when your thoughts are at too high a level, but it pays immensely, and I can guarantee from first hand experience to work incredibly well. The latter requires little finesse but a lot of grunt work.
While it's of course a personal opinion, I know first hand the first one to be a much better long term investment, and if it requires slapping people around a bit and getting some flak for it, **** it, I'll do it, because I see that as the reason of my continued efforts of moderation here.

Learning to backpedal on your knowledge to a point of branching to understand root issues differs greatly from forgetting about something for the sake of something else, and multiple tools become like having multiple texts and explanations for some very interesting subjects, which ultimately makes it a much more enjoyable experience than fighting the frustration of grunting your way through unfamiliar territory.

tc
02-18-2008, 10:06 PM
I think we are just missing a video on this topic...
XSI hard edges http://www.youtube.com/watch?v=Us_F5St6DvQ
the same video (http://www.xsi-brasil.com/videos/XSI_Hardedges_media/XSI_Hardedges.avi) with a better resolution.

hope that helps :)

sacslacker
02-18-2008, 10:31 PM
You're right Jaco and the information you volunteer is very much appreciated. The migration from Maya to XSI isn't too bad but there are a handful of little things that do require one to think differently which ultimately, is a good thing I think.

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