Clever way of rendering trees - is this possible in UE4?

I looked at the Unigine Valley benchmark demo today and saw something very interesting.

They render tree leaves with only one alpha masked polygon and then rotate that polygon so that it always faces the players viewing direction. That way, you always see it from the front side. The effect works so well, I did not notice it for a very long time, in fact you never notice it, unless you come from the render business and dissect everything. But even then it blend perfectly and natural to your eyes.

I made a quick sketch of what they are doing. No matter where you move the player, you will always see the alpha masked polygon like it is marked in red.
It should be much more effective that the current way with crossed polygons etc., if it is possible at all in UE4.


That’s what Speedtree does, you have the option of having those parts of the tree always face you or you can have them static.

I will throw my Xfrog away and get Speedtree!

Can someone confirm this works? I think engine would have to support such behavior?

What do you mean “confirm it works”? That’s literally just Math and common shader code for a billboard since the late 80s…

Yeah it’s called a billboard and used most times as part of the LOD. Some particle effects do more or less the same thing

Niagara trees sound like they could be a fun experiment…

It’s called billboarding and existed back in the 90s
Here’s an example how not to do it:

^This is basically it but on larger scale

Check out this Plugin - it creates billboards for any mesh
rdLODtools in - UE Marketplace