[Feature] Support Detail Map

[MJacred]

place different mesh according to a "detail map" (cluster mask code can probably be re-used?)

• for reference, see hterrain: https://hterrain-plugin.readthedocs.io/en/latest/#detail-layers
• being able to draw these in the addon would be great (can be used for cluster masks as well)
• "Scatter - Multiple" seems to suffer from overlaps

so that instead of grass (or empty spots) there clumps of flowers, stones, etc. placed

• having this as a feature makes it easier to prevent weird overlaps between multiple scatter nodes

EDIT: some notes/thoughts

• the 4 color channels can be used to draw/place 4 different Meshes in same splatmap and at the same time prevents overlaps -> though, I imagine there will be edge cases if mesh dimension difference is too big where the user has to finetune the drawing (or erase some color info)
• use the data from the polygon to create triangulated mesh, on which the user can draw the splatmap

[addmix]

I don't see how this could be integrated into scatter, considering that there is no mesh to draw a detail map onto. Beyond that, if you are using terrain, and wish to have a detail map, why not use the detail map included with terrain?

[MJacred]

One way to get that mesh is: Based on the source data (the polygons), create a simplified triangulated mesh. The user can draw on that mesh.

The terrain was just an example for illustration and implementation reference. A terrain system has a very limited use case range. Scatter, on the other hand, can be used on almost anything, anywhere: on houses, inside houses, in concrete cities.

[HungryProton]

That's a feature I didn't include in the add-on on purpose, as I wanted to avoid hand drawing anything. That's the reason it uses 3D paths as a main delimiter by default (although, this will change a little in Godot 4).

I tried to come up with various designs for this, but nothing was good enough, and it only increased the add-on complexity, so the idea was dropped.

[MJacred]

I see

Hm… There is one design I think should be relatively simple, yet powerful (at least regarding fixing overlaps)

• the user provides collision per mesh type
• define placement priority number per mesh type
• allow baking of a specific Multi-Scatter
• check for collisions and remove those with lower priority

what do you think?

[HungryProton]

If this is mainly about overlaps, then I'd suggest using a single scatter node with multiple scatter items and a Poisson distribution (Poisson is slow I know...). This way you're guaranteed to avoid overlaps without the extra complexity.

Do you have a concrete example or screenshots of what you're trying to do?

[MJacred]

Does the Poisson distribution take the different mesh dimensions into account?

If this is mainly about overlaps

It's also about accurate placement… but maybe using noise mask is sufficient.

Do you have a concrete example or screenshots of what you're trying to do?

I'm currently in the preparation step before props placement.
the goal is to be able to quickly place smaller props of few types indoor and outdoor (some some random rotation and scaling, latter within certain range). The props range from vegetation to small everyday items scattered on the ground

[HungryProton]

:thinking: If I can access and run the physics engine from the editor, maybe I can create a new modifier that physically spawns rigid bodies the right size in the scene, wait until they settle and save their position to place items there (and removing the physics objects).

But the detail map... the bigger issue is that Scatter isn't designed for really large areas, partly because using a particle shader is always more performant than using a multimesh. Maybe that's something that could be added, but that a pretty big feature I won't be able to work on before a while.