Talk to me about billboarding, brehs. Do you billboard grass or instance them? Do you billboard...leaves? Do you billboard entire trees?
Or, is billboarding mainly for smoke / particles?
>>515079
If you wanna make something like a vast forrest with tens of thousands of trees a billboard system is the only way you are gonna make it happen on current hardware.
Here's a rundown of how these things works: You have a mesh with several thousand quad polyogns with all their 4 vertices condenced to a single point everywhere where a tree is located.
These are used by a mass billboard shader that uses some smart code to displace these 4 corners of the polygon based on their UV coordinates and the viewing vector to make them always face the camera.
This way you can have several thousand of billboards quickly sorted and oriented towards camera trough fast and cheap calculations.
These mass billboard trees then have a draw distance over which they're set to be transparent, say anything closer to 200 meters have 100% alpha and then fades to solid over 50 meters out to 250m.
You then store the location of every three in a script that continously spawn a few hundred to low thousandsactual mesh tress for every point that is closer than 250 meter to camera.
The effect can be a near seamless fade of mesh to billboard if such a system is set up nicely.
>>515098
So you're saying that your billboards just have a 2D picture of a tree as an alpha cutout that use the camera up/right vectors to look at the camera (and constrain to horizontal rotation).
I get that.
Are you saying that the billboards themselves don't accept 3d lighting information and just be the input tree texture? Are you saying that only near trees should be real 3d and thus have real 3d lighting calculations on them?
>>515098
...is the only way...
Not true. Here is an Forrest rendering with 47 Billion Poly, GI and DOF, rendered in 207 seconds on my I7 (with 1GB of Ram used).
>>515130
>realtime