Rewrite the GPU Lightmapper's indirect lighting logic to match Godot 3.5's CPU Lightmapper.

Port over the logic from Godot 3.5 for indirect lighting. This should fix many issues about indirect bounces causing more energy and improve the overall quality of the result.

1 files changed, 31 insertions, 21 deletions

diff --git a/modules/lightmapper_rd/lightmapper_rd.h b/modules/lightmapper_rd/lightmapper_rd.h
index 9537d5eae6..8c1c4deba6 100644
--- a/modules/lightmapper_rd/lightmapper_rd.h
+++ b/modules/lightmapper_rd/lightmapper_rd.h
@@ -40,6 +40,26 @@ class RDShaderFile;
 class LightmapperRD : public Lightmapper {
 	GDCLASS(LightmapperRD, Lightmapper)
 
+	struct BakeParameters {
+		float world_size[3] = {};
+		float bias = 0.0;
+
+		float to_cell_offset[3] = {};
+		int32_t grid_size = 0;
+
+		float to_cell_size[3] = {};
+		uint32_t light_count = 0;
+
+		float env_transform[12] = {};
+
+		int32_t atlas_size[2] = {};
+		float exposure_normalization = 0.0f;
+		uint32_t bounces = 0;
+
+		float bounce_indirect_energy = 0.0f;
+		uint32_t pad[3] = {};
+	};
+
 	struct MeshInstance {
 		MeshData data;
 		int slice = 0;
@@ -57,9 +77,10 @@ class LightmapperRD : public Lightmapper {
 		float attenuation = 0.0;
 		float cos_spot_angle = 0.0;
 		float inv_spot_attenuation = 0.0;
+		float indirect_energy = 0.0;
 		float shadow_blur = 0.0;
 		uint32_t static_bake = 0;
-		uint32_t pad[2] = {};
+		uint32_t pad = 0;
 
 		bool operator<(const Light &p_light) const {
 			return type < p_light.type;
@@ -206,24 +227,13 @@ class LightmapperRD : public Lightmapper {
 	};
 
 	struct PushConstant {
-		int32_t atlas_size[2] = {};
+		uint32_t atlas_slice = 0;
 		uint32_t ray_count = 0;
-		uint32_t ray_to = 0;
-
-		float world_size[3] = {};
-		float bias = 0.0;
-
-		float to_cell_offset[3] = {};
 		uint32_t ray_from = 0;
-
-		float to_cell_size[3] = {};
-		uint32_t light_count = 0;
-
-		int32_t grid_size = 0;
-		int32_t atlas_slice = 0;
-		int32_t region_ofs[2] = {};
-
-		float environment_xform[12] = {};
+		uint32_t ray_to = 0;
+		uint32_t region_ofs[2] = {};
+		uint32_t probe_count = 0;
+		uint32_t pad = 0;
 	};
 
 	Vector<Ref<Image>> bake_textures;
@@ -252,11 +262,11 @@ class LightmapperRD : public Lightmapper {
 
 public:
 	virtual void add_mesh(const MeshData &p_mesh) override;
-	virtual void add_directional_light(bool p_static, const Vector3 &p_direction, const Color &p_color, float p_energy, float p_angular_distance, float p_shadow_blur) override;
-	virtual void add_omni_light(bool p_static, const Vector3 &p_position, const Color &p_color, float p_energy, float p_range, float p_attenuation, float p_size, float p_shadow_blur) override;
-	virtual void add_spot_light(bool p_static, const Vector3 &p_position, const Vector3 p_direction, const Color &p_color, float p_energy, float p_range, float p_attenuation, float p_spot_angle, float p_spot_attenuation, float p_size, float p_shadow_blur) override;
+	virtual void add_directional_light(bool p_static, const Vector3 &p_direction, const Color &p_color, float p_energy, float p_indirect_energy, float p_angular_distance, float p_shadow_blur) override;
+	virtual void add_omni_light(bool p_static, const Vector3 &p_position, const Color &p_color, float p_energy, float p_indirect_energy, float p_range, float p_attenuation, float p_size, float p_shadow_blur) override;
+	virtual void add_spot_light(bool p_static, const Vector3 &p_position, const Vector3 p_direction, const Color &p_color, float p_energy, float p_indirect_energy, float p_range, float p_attenuation, float p_spot_angle, float p_spot_attenuation, float p_size, float p_shadow_blur) override;
 	virtual void add_probe(const Vector3 &p_position) override;
-	virtual BakeError bake(BakeQuality p_quality, bool p_use_denoiser, float p_denoiser_strength, int p_bounces, float p_bias, int p_max_texture_size, bool p_bake_sh, GenerateProbes p_generate_probes, const Ref<Image> &p_environment_panorama, const Basis &p_environment_transform, BakeStepFunc p_step_function = nullptr, void *p_bake_userdata = nullptr, float p_exposure_normalization = 1.0) override;
+	virtual BakeError bake(BakeQuality p_quality, bool p_use_denoiser, float p_denoiser_strength, int p_bounces, float p_bounce_indirect_energy, float p_bias, int p_max_texture_size, bool p_bake_sh, bool p_texture_for_bounces, GenerateProbes p_generate_probes, const Ref<Image> &p_environment_panorama, const Basis &p_environment_transform, BakeStepFunc p_step_function = nullptr, void *p_bake_userdata = nullptr, float p_exposure_normalization = 1.0) override;
 
 	int get_bake_texture_count() const override;
 	Ref<Image> get_bake_texture(int p_index) const override;