Uv Texturing And Planar Projection Make Problems

[hendrik79]

I don't get along with that problem and would be really glad for any hint:

I have got a maya 5.0 scene and this one is textured using the UV tools like polyTweakUV, etc. This circumstance makes big problems when I open the scene in deep exploration or export it to a proprietary file format. The result looks like all UV coordinates are wrong and the texture images are distorted.

Normally I use the planar projection for texturing. Using this method on that file does not work, either. Only after deleting the polyUVSets by executing the delete poly uv sets from the edit polygon menu does allow me to use the planar projection method. If I don't do this step changing the planar projection setup has no effect on the texture image.

I tried to delete the polyUVSets and retexturing the model using the planar projection (that normally works fine). But in Deep Exploration the scene looks bad, too.

So I tried to delete anythin that has to do with UVs and textures and materials - just broke it down to have the pure geometry. And I retextured my scene. But the result didn't change.

I am a bit frustrated on that, but I am sure that the problem has to do with the UVs and maybe different coordinate systems of UVs and how MAYA works with them. Actually in any case MAYA displays the scene as desired. The problem always occurs using different Viewers (like DE or after file export)

So I would be really glad if you have got some hints on that case. Maybe you have got some different ideas what to try?

Thank you in advance,

Hendrik.

[joojaa]

for clairty of things when you say planar projection do you mean uv projection or a texture projection?

Since normaly most exporters/ importers dont understand texture projected textures. Forthe simple rerason thet they arent realy something thets usefull for deforming modells in game eingenes.

[hendrik79]

Normally I use the planar projection tool for texturing. But in this case both methods (the uv texturing and the planar projection) does not work.

Hendrik.

[joojaa]

planar projection tool? no such tool in my maya, i do hower have 2 different things could be called planar projection. the polyPlanarPojection node AND the projection node.

You seem to understand uderstand that theres 2 different things thats can be called planar projection. the other is a UVing tool and the other is a texture to 3d texture conversion in the shading network. Bacuase most porters have NO idea of shading networks they will have absolutely NO idea on what you type on yoru texture placemment nodes or what you type onto your texture projetion is part of your shading network nodes.

BUt you muust be a bit EXPLICIT whan you talk about theese things or the coversation turns realy CONFUSING-

ON the otherhand you can do a planar projevction that does a planary projected UV, wich should work as long as you do not rely on fiddling the uvsets. Since heres the thing when it comes to multitextring most generic porters have no idea on that whatsoever.

So if you hawe two uvsets or more then it means that a ) the porter and the target format must support it in some way. b )The porter must support shading network scanning bacause its the only way you can know what is connected to what uv. NAd becaus ethis is hard most dont implement this at all!

And why do you use the deep exploration to do the proting why dont you just write a maya exporter teht does exactly what you want?

[hendrik79]

sorry if my explanation was a little bit confusing...

Actually I am not an expert in MAYA and I just have a small overview. A time ago I created a couple of tools that do texturing. I have never had a view on other types of texturing method, because I am always using this tool. This worked fine until I get a model from a thirdparty and know I have the problems described above.

To make things clearer I describe the way that I am texturing and postprocessing the models:
I have a MEL script for creating a planar projection. First this one assigns a texture material to a selected face. Doing this there is created a shading node with option "-asTexture file". Then there is created a shading node with option "asShader" using the blinn shading method. Both nodes are connected throug outColor and surfaceShader.

After this step the texture file is loaded and assigned to the face. Now I need a manipulater to change the texture settings. For this I create a polyProjection of planar type while the face is selected. The result is the planar projection of the texture and I can move the manipulater and the texture images moves the same way.

When editing the thirdparty models this tool fails. When I want to change a texture using the common way of texturing, the new texture file is assigned correctly, but moving the manipulator does not move the texture image. This problem can be eliminated by calling the "Delete Current UV Set" command before. After this the texturing tool of mine can be used as desired. I can retexture the face and moving the manipulator moves the texture images as well.

But the deleting the current uv set can not be the final solution, because there are still some problems in the postprocessing. After having completed the models I would like to export them in my own file format. Until today this has never been a problem. The UVs have always been exported correctly. So I don't expect any errors in my exporter and in my texturing tool.

But exporting the thirdparty models the texture images are distorted. Retexturing with my tool as described above does not change anything. I use deep exploration only for a brief check up. When the maya model looks nice in deep exploration I export the model using a maya plug in.

I expect the problem at the UV tools that are used. The shading networks are more complex, too. They have got a uv chooser, a place 2d texture a file and a lamber shader. Using my tool there is only a blinn shader and a file.

So I hope you understand things a little bit better.

[joojaa]

Okay are your object pure trieangles when you texture them? if not then you might get a different triangulation and this a different inetrpolation of the mapping!

[hendrik79]

hm, this is a good idea I haven't thought of before. But this doesn't work, either.

I tried to delete the uv set, to delete the uvs and to create new uvs based on the camera, normalized, etc. Actually I think that I tried out any combination of commands in the polygon edit menu

[joojaa]

yes but triangulation istelf causes the mesh to do bad uv layouts because of interpolation so atleast on atriagulated mesh maya should show the exqact sam syptoms as the game eingene.

This is not atriivial limitation its one thet you realy cant circumvent on modern graphic accelerators in fact ist been described in the mr mavual faily well... It applies to quads thet are not planar causing wonkyinterpolation of stuff

i could do a picture for you but you coudl equaly easily jsut read thsi in your maya docs.

But i cant realy find anything esle it could be? unless the exporter realy has some limitation yoru not in know of.

[joojaa]

400) {this.resized=true; this.width=400; this.alt='Click here to open new window';}" onmouseover="if(this.resized) this.style.cursor='hand';" onclick="if(this.resized) {window.open('http://www.hut.fi/~joojala2/highend/UViterpolation.gif');}" />

argh highend sshrinks images to some (size uck click on it to se it aaed)!

Does the problem look like this. IF not then the problem probably lies in teh fact that the exporter interprets something wrong!

THis happens becaus ethe intorpolation happens on teh triangles NOT any other interpolation wich people asume. THe image iteslf is a pure blue and red filtered vertical ramp!

[hendrik79]

hm, acutally the result I get in deep exploration is sometimes a distorted image like someone would mix the uv coordinates and sometimes one sees no texture, what can be a result of wrong texture coordinates, too.

But my question is: Why does the scene looks correctly using MAYA and why the same file incorrect using deep exploration? What does MAYA do what deep exploration not do? Curiously is one thing, too: When I delete all faces except one face and do the delete uv sets and retexturing it, everything is okay. When I have got more then one face, this fails.

Hendrik.

[joojaa]

QUOTE(Hendrik79 @ 09/21/05, 05:19 PM)
But my question is: Why does the scene looks correctly using MAYA and why the same file incorrect using deep exploration? What does MAYA do what deep exploration not do?  Curiously is one thing, too: When I delete all faces except one face and do the delete uv sets and retexturing it, everything is okay. When I have got more then one face, this fails.
Hendrik.
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hard to say i woudl stipulet that may does ALOT deep exploration does not. Se the thing about 3d and export is that unless you know exactly how teh exporter works you cabnt realy rely on it. Se there exsists no universal exporter, infact there exsists no unversal way ouf doing 3d graphics either. Soore most work on triangles but thenegain not all do for example prman untill very very new incarnations didnt liek triangular stuff at all.