Vertex Color or Alpha in Hypershade

[ericne]

Hi,

Using Maya 6.0, I'm trying to blend between two textures in a layered texture based on the interpolated vertex color or vertex alpha (I'd be happy with being able to access either). However, I cannot find a way to access either value from within the hypershade, such that I can insert it into my shader network. If I needed to do this for a small mesh I could use an alpha map, but since I want to do this in a highly tesselated terrain mesh, alpha maps would be too memory intensive and cumbersome. Thus, I want to be able to paint my terrain, such that depending on the value, one texture or another is used. The final effect would be identical to what Unreal does for terrain layers, which can be seen here:
http://archive.gamespy.com/articles/march0...s/torlan/10.jpg

Now, I know that version 5.0 of the Maya Bonus Tools contains two plugins that may do the trick "cvColorShader" and "hwColorPerVertexShader," version 6.5 only contains the latter. However, neither seem to be available in the Bonus Tools for Maya 6.0, even though the help files mention them. Does anyone know why this is the case? Alternately, can anybody suggest another way that I could access either vertex color or vertex alpha info from within the hypershade such that I can implement this feature.

Thanks for the help,

Eric

[joojaa]

cvColorShader can be found in maya devkit now all you need i s to compile it and go...

[ericne]

I've been playing with it for a while now, but unfortunately without success.

Does it work for you in your version of maya? I compiled it in and it is not running correctly for me. I traced it to this line always resulting in the status being set to MS::kFailure thus not computing the color values for any pixel:

MPlug dagSetMembersPlug = MFnDependencyNode(shadingEngineNode).findPlug(
"dagSetMembers", &status );

If I comment out the entire compute function it does actually return whatever color or alpha values I specifically tell it to, but in and of itself it doesn't seem to work at extracting the vertex colors, at least on Maya 6.0. Any ideas why this could be?

Thanks for the help!

[joojaa]

interesting i loaded Plugins.sln into visual studio.net and compiled just that plugin and it worked just as i expected it to! Are you sure your vertex colors are actual vertex colors and not some blind data?

[ericne]

Yeah. I really don't know what could be the case. Which version of Maya are you using? I'm running 6.01 to be exact.

I've setup a small test file containing 1 polygon cube. To that cube I've selected different vertices and selected Edit Polygons -> Colors -> Apply Colors. I've colored it with the left side black and the right white, and the top with an alpha of 1.0 (solid) and bottom with an alpha of 0. It looks correct when I set "Display Colors" to on in the Mesh Component Display section of the pCubeShapeX option menu. Also if I apply the "hwColorPerVertexShader" also from the devkit plugins to the cube, it also looks correct. If the vertex colors are somehow wrong, I don't know how it could be the case.

What proceedure are you following to use the cvColorShader in your hypershade? I'm using it as I would use a sampler info, aka I'm just creating the node and manually setting in the connection editor the outAlpha of the cvColorShader node to connect to the in alpha of my layered shader. I've also tried connecting the outColor of the cvColorShader directly to the "color" value of my blinn shader as a test, but that only shades the entire cube black. Those are the only such connections that I make, outColor or outAlpha directly into the Color or Alpha input of some other node within my shader network. Are you using it in a different manner?

Thanks again for the help.

[joojaa]

6.01 but im starting to tool up tpo 6.5.

just created the node and connected it to my shading networkd normaly,