Tree asset image

A project utilizing Unreal Engine Virtual Production VFX workflow needed a blossoming apple tree asset which had to be both detailed and optimised enough to use as the realtime rendered background on the LED wall.

Geometry

It was quite challenging at first to come up with a Blender Geometry Node system which would have enough detail as well as control to get to the result which was needed.

Tree Geo Nodes

In the end I settled on a classic algorithm for tree modeling: Creating and scattering the branches one level at a time. This approach was a good middleground between complexity and controllability.

Vertex Data

Tree Gradient 0 Tree Gradient 1

In order to efficiently animate the tree in Unreal Engine I also needed to create a few “gradients” across the tree structure. This allowed me to isolate and add motion to different parts of the tree in the unreal engine shaders.

Optimisation

Tree Lod 0 Tree Lod 1

The tree had 2 LOD levels. The main difference was in the leaf nodes:

  • LOD0: 3D small branches, leaves and blossoms
  • LOD1: texture planes in place of the above

The trunk and larger branches did not contribute enough geometry to warrant optimisation in our project context.

Virtual Production

I assembled the scene in Unreal Engine and setup the systems for virtual production workflow to display the scene on the LED wall with our camera tracking solution.