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Tree and foliage materials for the new PBS renderer

Hi,

I am having some difficulties in getting trees (especially the leaves) and foliage looking as great as the other (anorganic) materials in UE4. Now, the new Blueprint Office project contains very nice examples for both, however the tree and foliage shaders are looking quite complicated. I’d be interested in some of the reasoning behind those shader graphs, e.g.

  • why those FuzzyShading and ConvertFromDiffSpec nodes, and why are you deviating from the standard “metallic is either 0 or 1 and leave specular alone” rules
  • the use of fresnel reflection
  • what exactly is that COG texture in the subsurface scattering part

That would be awesome, thanks!

If you wan’t realistic trees, trees done with PBR guide lines (consistent shading behavior regardless of lighting conditions), it is something that simply can’t be achieved right now in UE4.

Foliage need special lighting mode, for two sided rendering (and even for meshes that have thickness), as in real life foliage is shaded pretty uniformly with little variation depending on their leaves density.

Foliage in BP example is basically one ugly hack using Emissive node for tree (which is ridiculous if want want good foliage material for different lighting conditions).

FuzzyShading is used to add bit of color variation over leaves.
Fresnel is used to mask out Subsurface color, so it will only occur on outer branches.
COG texture is just random texture that is supposed to add variation to Subsurface Color.

The Special Foliage_Lighting mode should be added to material editor. Though there is no ETA on it. If someone is cleaver enough, please try to create it and make pull request (;.

Hello, I was able to get some pretty nice tree shading for my purposes. I’m posting some pics and my shader, which is pretty simple. The trick I found that really improved the look was unchecking tangent space in the material attributes for the leaves shader. That way, with the spherical normals imported from maya, the canopy shades as sphere of leaves, rather than per each leaf plane. I also played with the fresnel on the canopy and strangely enough it looked better when affecting the tangent space normal of my leaves instead of world space.

http://s12.postimg.org/gp3fifc8d/tree_shading.jpg

Thanks for your input! I’m somewhat happy that I’m not the only one struggling with this :slight_smile: Yes, those trees are definitely looking better than my feeble attempts, will try the trick with the object-space normals. However, there still seems to be a certain painted/cartoonish look to leaves/foliage in UE4, at least to my eyes those objects still look better in a “classical” non-PBR engine. Put differently, the visual improvement is definitely a lot bigger for those typical PBR materials like metal, stone etc. I really hope Epic will come up with a specialized lighting mode/graph node for organics.