strange texture behavior

[Lukich]

Hi, there. This must be somrething very basic, but I can't figure it out. Let's say, I have a basic grid, apply a uv project to it and put down a shader sop with some rust shader on it. Works like a charm, maps the image across the whole grid. However, if I go to VOPs, create the shader vop, and plug the Color Map node into the Cf, Houdini renders multiple copies of the image, one per face. Do you know what can it be? Thanks a lot!

Luka

[Marc]

Hey Luka

You need to tell the VOPnet to use the uv parameters of your geometry. By default each polygon will map from 0-1 (s,t).

To do this put down a shading layer VOP, append a vector to float VOP and then wire the first output into the 'u' parameter of your colormap VOP and the second into 'v'.

The third one, I'm guessing would be 'w', but even after all this time, I'm still not sure what the w parameter will do

Hope this helps

Marc

P.S. If you change your polygon grid to NURBS, then it will assign the texture correctly anyway. This is because the s and t map across the entire NURBS patch by default.

[Lukich]

Groovy! Thanks a lot, Marc! I have to go with the polygon because my actual geometry (grid's just an example) is very complex and converting it to nurbs would take hours. Thanks again

[Keyframe]

One other thing that might be worth noting with regards to NURBS patches and uv coordinates: While it is true that NURBS patches have an inherent set of uv coordinates, it is worth noting that an "explicit" uv attribute is not created, and hence, you will not be able to preview the texture in your viewport.

In order to do that, simply put down a UVTexture SOP, and set the texture type to rows & columns... (note that this actually creates an attribute called uv)

That messed with me for a few hours, so I thought i'd pipe up.

Cheers,

G

You need to tell the VOPnet to use the uv parameters of your geometry. By default each polygon will map from 0-1 (s,t).

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