I just do basic things , no fancy stuff :

I created a cop network inside /obj
inside the cop network, I added a 'fractalnoise' node. I can see the noise image in the scene view.
I added a previewmaterial node in the cop net.
Connect the output from fractalnoise to the 'height' of the previewmaterial.
Now in the scene view , I can't see the fractal or texture , it's just white.

I follow this video and the grid should look displaced by the fractal like this one :
https://youtu.be/ho2iQckcZ9c?t=337 [youtu.be]

what is wrong ?

What is your height scale set on the preview materail.

For me, using all the default settings I actually have to reduce that scale(initially set to one) to bring down the displacement to more pleasing levels.

BabaJ
What is your height scale set on the preview materail.

For me, using all the default settings I actually have to reduce that scale(initially set to one) to bring down the displacement to more pleasing levels.

Everything using default value - no parameter changes at all. I think I should see visible spikes. But I only got simply flat surface.

Btw , I'm using osx version of Houdini 20.5.278. Maybe a bug ?

metaclay2
osx version

Perhaps it is a bug for osx...I'm using windows

Post your hip...I'll open the file using windows and if I don't get your 'error', then definitely it's a bug for osx.( could be related to the viewport as I see a long discussion about that for mac on the forums here).

Otherwise it's possible you may have made a parameter change and forgot about it?

BabaJ

metaclay2
osx version

Perhaps it is a bug for osx...I'm using windows

Post your hip...I'll open the file using windows and if I don't get your 'error', then definitely it's a bug for osx.( could be related to the viewport as I see a long discussion about that for mac on the forums here).

Otherwise it's possible you may have made a parameter change and forgot about it?

Confirmed it's a bug on OSX version - running on macbookpro M1 max.
It works fine on my windows (tested just now)

Thanks man.

metaclay2
Confirmed it's a bug on OSX version - running on macbookpro M1 max.

I wouldn't say this is a bug, SideFX described it in the documentation. New COP requires vulkan viewport, but it is not implemented on macos. I also faced this problem

https://www.sidefx.com/docs/houdini/news/20_5/viewport.html [www.sidefx.com]

- Native display of COP nodes in the Scene Viewer.
- The Vulkan viewport isn’t supported on macOS. MacOS uses the OpenGL viewport renderer.