Tessellation and Foliage cause the Video Driver to crash

Hi guys! The issue is present in 4.16

This is still present in 4.21 but only occurs when dithered LOD is enabled on the tessellated material

This is still present in 4.21 even when I have dithered LOD off. Still not sure what’s up.

still having this issue on 4.24

at this point removing any bias or pulling the height from the texture’s Red channel doesn’t “fix” it anymore. the only way to “fix” it is by disabling Dithered LOD Transition

4 years later, it’s still impossible to have tessellated tree trunks ;(
can we kindly ask this to be looked into?

Yep, just found this bug report when investigating huge slowdowns after implementing tass on foliage. Can confirm that it still doesn’t work properly in 4.25 (not moved to 4.26 yet)

Foliage + Dithered LODs + (Tasselation + VertexNormalWS) = Hude FPS drop

Take one out of equation and it “works”

  • Avoiding VertexNormalWS directly and passing thru CustomizedUV from vertex shader - slowdown
  • Transforming [0,0,1] to WorldSpace - slowdown

Till fixed (never?) i’ve worked around the issue by constructing approximate vertex normal in vertex shader (using local vertex position some math and transforming to world) and CustomizedUVs.
Even with this some small negative bias causes slowdown…