This is a Houdini 6.0 Question. I need to know how to apply a Surface Displacement at the SOP level and not at the SHOP. In Houdini 5.5 you can just use a Project UV Texture or one of the other Texture SOPs and reference the uv vector into parameter in the Vex. However when I try this in Houdini 6 the SOP Geometry disappears. I tried using the shader SOP node with the UV Project Texture node but I have not had any luck. How do you pipe the values from the SOP Geo to the P value in the Vex in Houdini 6.0? I can't seem to find any documentation on this. I saw the global variables but I guess I am still not getting the right values piped in or something.

Cheers,
Nate Nesler :cry:

Are you writing shaders or using VOPs?

How do you pipe the values from the SOP Geo to the P value in the Vex in Houdini 6.0?

P is a global variable in the Sop context so just use P. It is read-write.

example shader code to displace along a point normal where P is the incoming point and N is the geometric normal if N doesn't exist explicitly:

…
/* Calculate the signed noise */
pp = vs_noise( (P+iseed) * freq + offset) * amp;
pp *= N;
P += pp;
}


VOPs network:

global(P)———————————-(wired in to displnml(P))

importattrib(uv)->vecttofloat->colormap(uv)->avgcomp->displnml->output(P N)

Now in VOPs go up one directory to the VOP node and rename the SOP Type Name to be something like VEX Map Displace. Now in SOPs, tab find your node and add it to the chain after the uv's are created.

I tried using the shader SOP node with the UV Project Texture node but I have not had any luck.

Custom VEX nodes are accessed the same way any tool is once they are compiled and installed correctly. You only use the shader SOP to apply shaders for rendering. When you hit the tab key, do you see your custom VEX Sop?