Getting tangent or binormal for a sop in GLSL?

Beginners
1

Hi,
I am writing a deformer in glsl for a sop that comes into a geometry comp. For my deformer to work well, I need to pass in a tangent and/or a binormal. I get the normal in the glsl as ‘N’. Is there any way to get the other value?

Thanks in advance

2

You need to create the tangent attribute. You can use the Attribute Create SOP to do this. You can use a Phong MAT with normal mapping active and output the GLSL code from that to see how to use the N and T attributes to create the binormal.

3

I got it. I tried that, but I had to declare in the vertex shader:

in vec3 T;

Which I didn’t have to do for the normal

4

Yes, that’s correct. The only attributes which are declared for you are P, N and uv[]. Any other attributes will need to be declared manually