Foliage + Lightmaps is broken/bugged/dysfunctional - Detailed explanation

[brisck1]

@IronicParadox;666430

Read up on draw calls. I’m almost positive it’s having to make a draw call for each of the lightmaps; despite the trees all being duplicate instances of each other. The engine isn’t moving whole “boxes of paper” at once, it’s having to move “pieces of paper” one by one. So the character model analogy doesn’t work.

I’m not sure what you mean by the pieces of paper analogy, but I will do some tests on draw calls vs instances + lightmaps to confirm if this is correct. I’m also going to be exploring more dynamic solutions this week.

@KVogler;666480

I ran into a similar problem with railroad ties.
Made a blueprint that places ISM instances along a spline. Above a certain number of ties, the engine would give me the same warning.
I solved it by making the bp a mix of ISM and child actor components.
Now I have a BP that spawns actors that construct ISM instances.
So inastead of 1 actor with 100 ISM instances, I have 10 child actors with 10 ISM instances.
Works fine

That’s a cool way of approaching it, will definitely keep this in mind as I’m planning of doing something similar.

@KVogler;666480

Another idea:
Put half of the trees in a new sub level.
As lighting is built per level, lightmass will definitely not putting that in the same lightmap.

I experimented with this a while back but it didn’t seem to work - I think though I need to go back and try again in a more controlled test environment - I’ll let you know what turns up!

I’m also thinking of hiring a coder to look into this a little more since it’s kind of a big deal to my project.