Introduction to foliage

There’s three different groups of foliage in games; trees, bushes, and ground foliage (grass etc).

• Trees
  • Make the polygon density go lower the higher up the tree; the player is not there anyway
• Bushes
  • Build a couple of clusters, and use instancing tech to fill up the space required
• Ground foliage
  • Mesh normals should be pointing up

Modular foliage approach

Bark and leaves are separate materials and objects. Use SpeedTree to make clusters from the leaves and branches. Those clusters you can then use to make the final tree in a different SpeedTree file.

Creating the elements

Materials

Photoscanning

Alex Patel has a nice process on his Artstation https://www.artstation.com/artwork/58dPBz where he shows how he photographed the leaves and branches and then used Houdini for placement.

We can take this process and adjust it for our own needs. We’ll need a light tent, they are pretty cheap on Amazon or we can build one ourselves. Then we capture the foliage assets in multiple lighting angles. Then we generate a normal map using Substance’s Multi-Angle to Normal node https://substance3d.adobe.com/documentation/sddoc/multi-angle-to-normal-159451093.html https://substance3d.adobe.com/tutorials/courses/Art-by-Rens-Substance-3D-Designer-Scan-Processing

From there we can make a height map and all the other things flow from there.

https://youtu.be/7YGd3bcO_Ys Grzegorz Baran has a much more detailed tutorial on it, and more besides. https://www.artstation.com/gbaran/albums/653352

See also: https://youtu.be/gPBqrlUL1G8 Environment PBR Texture Creation using Photogrammetry - Tree Bark