Displacement not working (well)

anonymous_user_3346bd1b · October 16, 2018, 8:29am

Hi, all,I’m having some problems setting displacement material for landscape.

After several trials on displacement for landscapes fails, I start to verify the problem on a simple box
(The enable tessellation is ticked, the method is PN triangle)

So this is my material at first. Learned from this tutorial

Of course it fails

Then I find a post, which is telling me to do this…And it works (even when enable crack xxxxx option is ticked)
However, its displacement result is very sharp and not smooth. It is on a UE4 box.
No matter how much I put in tesselation multiplier, even 100, its still not adding enough triangles to the surface. What’s more, the material preview shows a black ball, and it is flickering between this result and correct shading result

It’s not until I’ve imported a plane from 3DSMAX with an exisiting 6x6 subdivision then I get this following smoother result

However, this is far from the effect in Quixel Mixer

Does anyone know how to achieve the correct result in the final image?

Raildex · October 16, 2018, 8:44am

Disable “Crack Free Displacement” and make sure your base mesh already has a good tessellation.

anonymous_user_3346bd1b · October 16, 2018, 8:53am

Hi Raildex, thanks for the help.
I was about the correct my post that I’ve unchecked the “Crack Free”…
So In unreal, if I want to get good tessellation result, I still need to have an already subdivided mesh to perform smooth displacement?

Raildex · October 17, 2018, 8:54am

You indeed need an already well tessellated mesh.
Unreal performs Tessellation up to 8 levels. everything above that would slow down or cost too much.
(Think of Tessellation to add small details)

anonymous_user_3346bd1b · October 18, 2018, 5:38am

Thanks a lot! That is caused by my limited subdivision level.