Greeting everyone.
I have two questions about displacement in Houdini:
1. Why can't we see the displacement of shader builder in 3d viewer but can see the displacement of principled shader what is the diffrence between them?
2. If we want to put a lot of trees on a displaced ground how to bring displacing information from shader to sop level? is this a good way to use displacing nodes in point vop for example or better option exists?
Really thanks.

Anyone?

Only one question per post, please.

OK. consider second question only.

Two approaches for question 2.
a) Bake the displacement amount into a map, and use the texture lookup to move the point for the tree instance.
b) Re-write the displacement shader in SOPs and apply the same displacement as in the shader directly using either a wrangle or a VOP network.

Really thanks Mark.
You talk about using texture lookup, what is texture lookup? is it a node?
Thanks again.

question 1: dofference is that shaderbuilder does not have any openGL properties, prebuild shaders does have them link to texture slots.

Check OpenGL parameters

Thank you so much martinkindl83.
I couldn't find any tutorial about OpenGL displacement except H15.5 quick start video about this!
Therefor I don't know how to use OpenGL parameters!
I want to create a simple displacement from scratch which can see in 3D viewport.
Can you guide me a little bit more?
Thank you.

What do you mean “from scratch?” The only displacement supported in the viewport is texture based, AFAIK. You can build a displacement shader from nodes, but only a single texture map can be linked to the viewport. You can link it by tagging the parameter with an opengl tag, associating the parameter with the opengl property.

It might be possible to create your own glsl shader for displacement, but there won't be any vex functions available, such as noise.

Thank you jsmack.
I bring in all OpenGL displacement parameters via edit parameter interface and now I can see displacement in viewport.
Just forget about from scratch.
I think that I've needed to create or use some nodes or digital assets in order to see displacement in veiwport!
Thanks again.