Texture TOP to manipulate UVs?

[rurik]

Hello
I'm trying to figure out how to use the Texture TOP to move a texture around on my 3d geometry.
I'm bringing in an FBX file with UV coords assigned to it, and would now like to translate the material I'm applying on the geo.
I tried doing that with the Texture TOP, but changing the projection method, or trying to translate things around does not work....
What is the workflow for this?

Thanks
Alex

[rurik]

Ok, after digging for the last few hours, I figured out how to use the Texture SOP in conjunction with the Material SOP to change the projection types on my geometry.

One thing I'm not sure I understand....Say I use the "Modified Source" projection type, as I want to keep my initial UV's, but just offset them, I can see that if I modify my scale parameter, the texture scales. However Offset does nothing...

Still trying to figure this out, but any tips would be most appreciated
Thanks
Alex

[rurik]

And to continue in the same vein, rotation works as well, both in the Texture and the Transform tabs....
What is the difference between those two tabs when it comes to those transforms?

[rurik]

Next steps in my exploration....Bring in the same geometry with no UV's at all.

Observation. Now the geometry comes in with a DAT that is identifying two groups...Not sure how that came in, but it is certainly very handy!

I am now mapping the same image to the geo, and I can see that the mapping is indeed not respecting the UV's, which is good. There are also no UV attributes

However I am still not able to offset the texture, even though I can scale and rotate...

What else can I try?

Thanks
Alex

[rurik]

OK, I think after two days of banging my head against the screen I have a working solution.
The trick is to move the offset in the Texture TOP by tiny increments. Somehow it seems that if you move it by high units there is no change. It seems like the default number in there should appear as a 2 digit float, because it is extremely confusing. I really only figured this out by accident.

A couple of things I noticed in case anybody is listening.

1/If you select an orthographic projection onto a surface, Touch will default to "fitting" the texture to the geometry, and thus distorting it. This is definitely not what you would expect from an orthographic projection and forces the user to do some un-necessary math to undistort the texture
2/As an alternative to the above you would want to use a flat or frontal projection. There does not seem to be such a thing? The Face projection does not do that, as it projects onto each face. I looked into "XYZ Position", but there is no reference to it in the docs, and it also does not seem to do flat/frontal projection. Am I missing something?

3/The SOP viewers are really useless to view texture projection. This looks like a clear bug to me. If you set your viewers to a certain view onto your geometry, then go up one level, when you dive back in, they are all reset to where they were. They also seem to sometimes "lose" the projection, reverting to a simple polygon display. Can't seem to figure out what does that.

Alex

[malcolm]

Yes since texture coordinates are always normalized (between 0-1) offsetting by 1, 2 3 etc will result in the same parts of the texture getting sampled for each pixel (when Repeat texture extend mode is used)

[rurik]

Interesting, where is the Repeat Texture extend setting?

Also, it makes sense that texture coords would be normalized, but the values should not be scrubbable above 1 in that case...

Alex

[TP]

Hi, is 'repeat texture extend' exposed to us? Did you find it Alex? I'd like to turn it off... I'm hoping to enable GL_CLAMP_TO_EDGE because I'm texturing with an orthographic projection.

Tom.

[rurik]

Yes, in the Phong MAT, select the type of map you want to use, and there is a pair of ">" signs that unfold all the Extend parameters.

Alex

[TP]

Great! Thanks Alex.