As there seem still to be a lot of folks looking for a solution to this.
I put a solution into Camera facing foliage for trees via material - #12 by kaidawai
The short answer is:
- There is no “offset problem”. Offset is fine. wrongish guesses brought this up.
- Pontius Karlsson does a partial Billbording by stretching the faces parallel to the camera.
- Unity has meter units whereas Unreal has cm so stretching by 1 unit has way more impact in unity(factor 100).
- early normalization destroyes the wanted form of a square and runs into division by zero. Pontius Karlsson did not do that and it breaks everything.
- billboarding by streching means, the model needs to be crafted that streching gives the desired effect(smaller faces).
- relationship between face size and uv/texture square size defines how much billboarding is done.
you find a solution for 100% billbording using Pontius Karlssons approach with a working shader: Camera facing foliage for trees via material - #12 by kaidawai