Can you generating foliage on a static mesh in unreal?

Shredd

G'day G'day
is there a way I can generate foliage on static mesh in unreal?
For example, I (like pretty much everyone) like using the world align blend to have a moss material blend on top of rocks, I was wondering if it's possible to spawn small moss cards using the same mask.
cheers in advance.

another caveman

With built in tools I don't know, I guesss you could blueprint something out. Else houdini engine is a good way to get that done if you don't need it edited at runtime.

poopipe

you can definitely blueprint it - you'll lose a lot of the benefits of the foliage system in terms of optimisation but if you made sure to use instanced static meshes it wouldn't be too shitty 

I'd probably use Niagra tbh - its got some really neat optimisations when you're spawning a shit load of stuff and it seems more useful to spawn moss over an area than on a specific rock

sprunghunt

The foliage system does draw on static mesh as well as the terrain. But it won't be able to access the mask that's inside of the material. You'd have to manually paint foliage onto the rock. 

For something like that I'd use houdini - but that might take a bit of time for you to learn. 

poopipe

Can Houdini generate positions to drive foliage rather than ISMs though? 
Does it make a difference? 

Shredd

Houdini could do it for sure. Since it doesn’t seem possible to do it in a shader, a mix of generating in Houdini or placing them on the objects in a 3d package. Along with the foliage painting tool is the way to go.. it’s a shame though. I’d of loved to spawn more or less moss based on parameters in a shader.. one day

poopipe

I'm pretty sure you'll be able to drive that through niagara - i'm just scratching the surface at the moment but given that it can place particles based on a texture .. 

the Houdini question is more to do with what happens to the instances 
ISM instancing only works within in a single actor so if you create a rock blueprint that spawns 1000 instances of a moss mesh via Houdini or whatever you pay for one rock mesh and one moss mesh
but
if you then add 99 other rocks you're paying for 100 rock meshes and 100 moss meshes 

The foliage system is afaik much better at dealing with that sort of situation 

Alex_J

I realize this is a bit dated but I wanted to suggest that there is a plugin on the marketplace called "simple scatter" and its perfect for this need. It's not one of those tools that has a bunch of crap you don't need - it replaces UE4 procedural foliage in a much simpler and artist friendly way.  it takes a landscape or static mesh target.

it works extremely simply with a few rules of height or angle plus you can input mask. 

I rate it five out of five stars.