Lighting shader constants.
static constexpr int32_t PBR_TEXTUREUNIT_ENVIRONMENT_DIFFUSE
static constexpr int32_t PBR_TEXTUREUNIT_EMISSIVE
static constexpr int32_t PBR_TEXTUREUNIT_BASECOLOR
static constexpr int32_t SPECULAR_TEXTUREUNIT_TERRAIN_DIRT
static constexpr int32_t SPECULAR_TEXTUREUNIT_TERRAIN_STONE
static constexpr int32_t SPECULAR_TEXTUREUNIT_TERRAIN_SNOW
static constexpr int32_t SPECULAR_TEXTUREUNIT_SPECULAR
static constexpr int32_t SPECULAR_TEXTUREUNIT_TERRAIN_BRUSH
static constexpr int32_t SPECULAR_TEXTUREUNIT_DIFFUSE
static constexpr int32_t SPECULAR_TEXTUREUNIT_NORMAL
static constexpr int32_t SPECULAR_TEXTUREUNIT_TERRAIN_GRAS
static constexpr int32_t PBR_TEXTUREUNIT_METALLICROUGHNESS
static constexpr int32_t PBR_TEXTUREUNIT_ENVIRONMENT_SPECULAR
static constexpr int32_t PBR_TEXTUREUNIT_NORMAL
static constexpr int32_t SPECULAR_TEXTUREUNIT_ENVIRONMENT
static constexpr int32_t PBR_TEXTUREUNIT_ENVIRONMENT_BRDF