Add per-environment geom visibility mask for heterogeneous entities

[Kashu7100]

Summary

Renderer-side support for heterogeneous entities — objects whose geometry variant only exists in a subset of environments. This is the gs-madrona analog of genesis-world#2958, which fixed the same class of bug in the pyrender rasterizer via a per-(primitive, env) env_active mask.

The gap

The geometry list in gs-madrona is global and shared across all worlds: every world creates the same numGeoms RenderEntity instances, and the only way to make a geom non-renderable was the global geomDataIDs == -1 geom-group filter, applied identically to every world (sim.cpp). There was no way to express "this geom variant only exists in envs X, Y", so heterogeneous variant geoms render in every world.

The change

Adds an optional per-(world, geom) visibility mask:

• New optional geom_env_mask kwarg on MadronaBatchRenderer.__init__ — int32 [num_worlds, num_geoms], 1 = visible / 0 = hidden. Defaults to None → fully backward compatible (all geoms visible everywhere).
• Flows through GSModel.geomEnvMask → H2D copy in Manager::Impl::make → Sim::Config.geomEnvMask → Sim::Sim, which disables the per-world instance's renderable when masked off.
• The per-world instance entity is still created (just non-renderable), so the exported [numWorlds, numGeoms] Position/Rotation/Scale columns stay aligned and the per-frame pose memcpy is unaffected.

The mask is consumed once at construction (heterogeneity is static), so there is no per-frame cost and masked geoms never enter the draw/BVH set.

Files

• src/bridge/mgr.hpp — GSModel::geomEnvMask
• src/bridge/sim.hpp — Sim::Config::geomEnvMask
• src/bridge/sim.cpp — per-world renderable disable
• src/bridge/mgr.cpp — H2D upload + wire-in + free
• src/bridge/bindings.cpp — optional geom_env_mask kwarg
• src/bridge/gs_madrona/renderer_gs.py — documents the new optional GeomRetriever contract

Build / test

Builds cleanly from source (Clang 18.1.8 bundled toolchain, CUDA 12.6): sim.cpp, mgr.cpp, bindings.cpp compile and link with zero new warnings; the resulting wheel imports and exposes the new geom_env_mask kwarg.

Follow-up (not in this PR)

The matching producer side must be implemented in the Genesis madrona GeomRetriever: emit geom_env_mask and full, non-compacted per-world poses for heterogeneous geoms — the direct analog of the vis/rasterizer_context.py change in genesis-world#2958.

Note

Draft — opened for review of the renderer-side approach before wiring up the Genesis producer.

🤖 Generated with Claude Code

[Kashu7100]

Local working directory where this branch was developed and built: /home/kashu/research/gs-madrona

[Kashu7100]

[Kashu7100]

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