Updates for procedural scenes: geometry, materials, instancing, transparency, point lights

[fbriggs]

• fwdtools.i2 (bug fix) — The vertex-color technique was hardcoding metallic=1, roughness=1, and double-applying vertex color. Point lights and envmaps had no effect on procedural geometry.

  • forward_lighting_ntex: albedo changed from vec3(1,1,1) → modcolor (vertex color becomes PBR albedo)
  • ambrufmtl changed from vec3(1,1,1) → vec3(1, RoughnessFactor, MetallicFactor) (reads material uniforms instead of hardcoded values)
  • Removed double * modcolor multiply — was squaring vertex color, killing envmap reflections
  • Passes vec3(1) as modcolor to _forward_lightingZ since the color is already in the albedo

• pbr.fxv2 (new features) — Transparency support for procedural geometry. Instanced rendering with vertex colors.

  • Added sb_cullcw_alpha state block (alpha blending + no depth writes)
  • Added FWD_CV_NM_RI_NI_MO_ALPHA technique (transparent vertex-color, non-instanced)
  • Added FWD_CV_NM_RI_IN_MO technique (opaque vertex-color, instanced)
  • Added FWD_CV_NM_RI_IN_MO_ALPHA technique (transparent vertex-color, instanced)

• pbrtools.i2 (new features) — Transparency, tint/opacity per object, instanced rendering with vertex colors.

  • ps_forward_test_vtxcol: output changed from (lit, 1) → (lit * ModColor.rgb, frg_clr.a * ModColor.a) — enables per-object tint and opacity via ModColor
  • Added ps_forward_test_vtxcol_alpha — transparent fragment shader with luminance-based alpha boost for glass-like specular
  • Added ps_forward_instanced_vtxcol_alpha — instanced transparent fragment shader (no luminance boost, instance alpha = final opacity)
  • Added vs_forward_instanced_vc — instanced vertex shader that reads per-vertex colors AND per-instance colors, multiplies them

• stdtools.i2 (new feature) — Instanced rendering needs to combine per-vertex colors with per-instance colors.

  • Added lib_pbr_vtx_instanced_vc — vertex-color-aware instanced vertex transform lib block

• fx_pipeline.h — Pipeline cache needs to distinguish opaque vs transparent permutations.

  • Added bool _is_alpha = false to FxPipelinePermutation

• material_pbr.inl — PBRMaterial needs new technique pointers and alpha blending flag.

  • Added technique pointers: _tek_FWD_CV_NM_RI_IN_MO, _tek_FWD_CV_NM_RI_IN_MO_ALPHA, _tek_FWD_CV_NM_RI_NI_MO_ALPHA
  • Added bool _alphaBlend = false

• rigid_primitive.inl — Alpha blending support and instanced rendering for procedural geometry.

  • Added #include <ork/lev2/gfx/material_pbr.inl> for PBRMaterial access
  • installInCallbackDrawable: checks _alphaBlend to set permu._is_alpha
  • Added renderInstancedEML() — instanced draw call
  • Added InstancedRigidPrimitiveDrawable — full instanced rendering drawable for procedural geometry

• pyext_gfx_lighting.cpp — Missing properties needed to create and configure dynamic lights from Python.

  • Added LightData.intensity and LightData.shadowCaster properties
  • Added PointLightData.radius and PointLightData.falloff properties
  • Added DynamicPointLight() constructor and .data property
  • Added SpotLightData.createNode() method

• pyext_gfx_pbr.cpp — Python needs to set alpha blending on materials.

  • Added PBRMaterial.alphaBlend property

• pyext_gfx_primitives_rigid.cpp — Direct GPU buffer upload and instanced rendering from Python.

  • Added RigidPrimitive.fromArrays() — direct GPU vertex/index buffer upload from numpy arrays
  • Added RigidPrimitive.createInstancedNode() — creates instanced drawable node

• pyext_gfx_scenegraph.cpp (bug fix) — Instance data bindings were hardcoded to InstancedModelDrawable.

  • Changed dynamic_pointer_cast<InstancedModelDrawable> → dynamic_pointer_cast<InstancedDrawable> in instanceData, setInstanceMatrix,
    setInstanceColor

• fx_pipeline.cpp — Pipeline cache index needs the alpha bit.

  • Added _is_alpha to genIndex(): index += (uint64_t(_is_alpha) << 6)

• material_pbr.cpp — gpuInit needs to load new technique pointers.

  • Added technique lookups for FWD_CV_NM_RI_NI_MO_ALPHA, FWD_CV_NM_RI_IN_MO, FWD_CV_NM_RI_IN_MO_ALPHA

• fwdnode_pipeline.cpp — Forward pipeline technique selection for new permutations.

  • Updated pipeline selection to handle instanced + vertex-color combinations
  • Handles _is_alpha flag for both instanced and non-instanced vertex-color paths

Tests

# Procedural PBR materials (gold, chrome, chalk, obsidian, copper, plastic, glass)
ork.lev2/pyext/tests/renderer/primitives/procedural_pbr/vtxcolor_materials.py

# Transparency (fixed alpha, animated opacity, animated tint, opaque-inside-transparent)
ork.lev2/pyext/tests/renderer/primitives/procedural_pbr/transparency.py

# Point lights (3 colored lights orbiting matte/metallic/mirror spheres)
ork.lev2/pyext/tests/renderer/primitives/procedural_pbr/point_lights.py

# GPU instancing (500 opaque + 200 transparent instances with animated transforms)
ork.lev2/pyext/tests/renderer/primitives/procedural_pbr/instancing.py

# Basic cube + sphere + light - are all 4 sides of the cube getting point light OK?
# Is the environment map's lighting contribution upside down?
ork.lev2/pyext/tests/renderer/primitives/procedural_pbr/basic_cube_sphere_light.py
# Same test with gold material instead of chalk:
ork.lev2/pyext/tests/renderer/primitives/procedural_pbr/basic_cube_sphere_light.py --gold

[fbriggs]

This might not be necessary, was an attempt to fix seams and nodes on spheres which may come from HDRI