Release v0.43.0

[sebcrozet]

v0.43.0

Breaking Changes

• The rasterizer now renders into a linear HDR film that is tonemapped on resolve, with Khronos PBR Neutral as the default tonemap operator. Existing scenes therefore look different (more filmic highlight roll-off, less hard clipping). Call Window::set_tonemap(Tonemap::None) to restore the previous look.
• Shadows are enabled by default. Lights now cast shadows (Light::casts_shadows defaults to true) whenever shadows are globally enabled, and the default shadow atlas is 4096² across 16 layers (~1 GB of GPU memory). Use Window::set_shadows_enabled(false) and/or set_shadow_resolution(2048) to reduce this.
• Custom Material3d implementations must target Context::render_format() (the Rgba16Float HDR film) instead of the surface format for their color attachment, or they fail with a render-pass-incompatibility validation error. A material is only invoked in the new transparent (order-independent-transparency) pass if it returns true from the new Material3d::renders_in_transparent_phase() (default false), so opaque custom materials need no other change.
• RenderContext gained phase: RenderPhase and shadow_bind_group: Option<wgpu::BindGroup> fields; Light gained radius: f32 and casts_shadows: bool fields. Code that builds or exhaustively destructures these structs with a struct literal must be updated (builder usage such as Light::point(..).with_intensity(..) is unaffected).

New Features

GPU path tracer

• Added a progressive Monte-Carlo path tracer (RayTracer) that renders the existing scene graph as an alternative to the rasterizer, via Window::render_raytraced and OffscreenSurface::render_image_raytraced.
  • Two backends sharing one WGSL kernel: a software compute-shader BVH traversal (default) and a hardware ray-query path behind the hw_raytracer feature, selectable at runtime.
  • Two-level (instanced) BVH so instanced scene nodes are traced once per mesh.
  • Unified PBR/BSDF surface model (diffuse / metal / glass), per-object materials and textures, area-light next-event estimation with multiple-importance sampling, thin-lens depth of field, and image-based lighting from an equirectangular HDRI.
  • Alpha (coverage) transparency; ambient acts as a uniform fill light; the window background color is shown on directly-seen ray misses without lighting the scene.
  • Edge-aware à-trous denoiser with first-hit albedo/normal guides (RayTracer::set_denoise).
  • BSDF setters on SceneNode3d (set_metallic, set_roughness, set_emissive, …).
  • Examples: raytracing, raytracing_bsdf, raytracing_denoise, raytracing_offscreen, raytracing_transparency.

HDR rendering pipeline

• The rasterizer now renders into a linear Rgba16Float HDR film and resolves it with a configurable tonemap operator (Window::set_tonemap / set_exposure).
  • Operators: None, Aces, Reinhard, AgX, Neutral (Khronos PBR Neutral, the default), and TonyMcMapface (baked CC0 LUT). The same operator applies to the path tracer's resolve.
  • Physically-weighted bloom on the HDR film (Window::set_bloom_enabled and related settings).
  • Weighted-blended order-independent transparency for the rasterizer (correct blending of overlapping transparent surfaces without sorting).
  • Examples: hdr_bloom, tonemapping, transparency.

Real-time shadows

• Added real-time shadow mapping for directional, spot and point lights, applied in the PBR lighting pass.
  • Directional lights use cascaded shadow maps (the camera frustum is split logarithmically, each cascade fit with a rotation-invariant, texel-snapped projection derived from the camera so shadows don't shimmer or degrade with scene size, and cascades are cross-faded across boundaries) for crisp near shadows with bounded far coverage.
  • Spot lights use a perspective map; point lights an unrolled cube map.
  • Castaño 2013 optimized PCF (tent-weighted 9-tap) for smooth, crisp edges.
  • Configurable: Window::set_shadows_enabled / set_shadow_resolution, plus cascade count, shadow distance, first-cascade bound and depth bias on the shadow mapper. Per-light Light::with_casts_shadows.
  • Example: shadows.

Auxiliary render outputs (AOVs)

• Added auxiliary render outputs produced by re-rendering the scene with dedicated materials (no path tracer required): linear depth, surface normals, and per-object segmentation ids (with a colorized variant).
  • Window::snap_depth / snap_normals / snap_segmentation / snap_segmentation_colored, a per-object segmentation id on Object3d, and an aov example.