@3D_Wave_Design, welcome to the community! I’m interested to hear more about what you want to do with making a particle world because there is a lot there left to interpretation. If you are thinking of a 3D world of meshes, we do not have mesh particles in the engine yet so growing your own forest with particles controlled by the texture on a mesh isn’t possible yet. We also haven’t implemented emission from a custom mesh yet as all of our emitters are known primitive shapes.
We want to implement both of these features in the future, but do have concerns about them while there are still a lot of engines requiring WebGL 1.0 and thus not able to take advantage of GPU particles. We are also limited to a single thread on the web which does limit some of the features we want to add based purely on the ability to use them and do other things in the scene.
@Deltakosh is trying to lead the charge for a solution for single thread web trap, and @sebavan has been following closely on the heels of Google’s efforts on WebGPU to integrate it into Babylon.js. You can see his low-poly forest populated on a texture in this thread about the Google I/O presentation. This one isn’t done with a particle system but rather thousands of individual meshes.
In the mean time, if you want to spawn billboard particles based on a texture, you will need to do some extra work to read the texture and extrapolate where particles in the emitter can spawn and then kill any spawned particles that are outside those limits. I hope this explanation helps a little and I’d be interested to hear more about what you are trying to do so we can identify where we may be able to add some support to make the job easier.