Read the buildings and props a map places from its compiled art (the
uncompressed worldbuilder stream + embedded DDS textures):
- ra3.models: BAB asset-stream parser (lazy slices), W3DMesh + D3DHierarchy
decode, DDS (DXT1/3/5 + uncompressed) decode, per-mesh bone remap and
bind-pose single-joint skinning, flattened to one world-space triangle soup.
- ra3.map: parse the ObjectsList chunk into (type, x, y, z, angle).
- ra3.terrain: render3d rasterises the scene over the raymarched terrain with
a z-buffer; gpu_terrain carries the scene for the GPU backends.
- ra3.vulkan: second pipeline + depth attachment, terrain.frag writes
gl_FragDepth, and a small depth bias keeps ground decals from z-fighting.
- objects.fx shaders (compiled to SPIR-V), embedded like scene/terrain.
Only opaque parts are drawn: FX-light billboards (DefaultW3D.fx / BasicW3D.fx)
and damage-fill shells (BuildingsGenericDamageFill.fx) are skipped, since the
latter paint the wrecked interior (e.g. orange CBBuilding_Wood) over the shell.
Ground-decal meshes with no diffuse role and the Road templates themselves are
still not drawn.
The engine now runs on a plain Web Worker (no SDL, no PROXY_TO_PTHREAD: in a pthread Emscripten proxies every filesystem syscall to the main browser thread, where synchronous XHR - and thus FS.createLazyFile - is forbidden). A page/worker pair transfers an OffscreenCanvas and forwards DOM input; assets load lazily from an embedded manifest, so entering a map fetches only that map and its tiles.
Presentation: ra3.webgpu (WebGPU via Emscripten's emdawnwebgpu port, WGSL shaders, the default on wasm) and ra3.wasmgl (WebGL2, GLSL ES). The legacy SDL ra3.webgl backend is removed.