Introduce eye_offset for correcting stereoscopic reflections

Use view instead of vertex for reflections.

5 files changed, 16 insertions, 6 deletions

diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_clustered.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_clustered.glsl
index 92c4fc3d67..b992e948c3 100644
--- a/servers/rendering/renderer_rd/shaders/scene_forward_clustered.glsl
+++ b/servers/rendering/renderer_rd/shaders/scene_forward_clustered.glsl
@@ -634,7 +634,11 @@ void fragment_shader(in SceneData scene_data) {
 
 	//lay out everything, whatever is unused is optimized away anyway
 	vec3 vertex = vertex_interp;
+#ifdef USE_MULTIVIEW
+	vec3 view = -normalize(vertex_interp - scene_data.eye_offset[ViewIndex].xyz);
+#else
 	vec3 view = -normalize(vertex_interp);
+#endif
 	vec3 albedo = vec3(1.0);
 	vec3 backlight = vec3(0.0);
 	vec4 transmittance_color = vec4(0.0, 0.0, 0.0, 1.0);
@@ -1191,7 +1195,7 @@ void fragment_shader(in SceneData scene_data) {
 	if (sc_use_forward_gi && bool(instances.data[instance_index].flags & INSTANCE_FLAGS_USE_VOXEL_GI)) { // process voxel_gi_instances
 
 		uint index1 = instances.data[instance_index].gi_offset & 0xFFFF;
-		vec3 ref_vec = normalize(reflect(normalize(vertex), normal));
+		vec3 ref_vec = normalize(reflect(-view, normal));
 		//find arbitrary tangent and bitangent, then build a matrix
 		vec3 v0 = abs(normal.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(0.0, 1.0, 0.0);
 		vec3 tangent = normalize(cross(v0, normal));
@@ -1309,7 +1313,7 @@ void fragment_shader(in SceneData scene_data) {
 #else
 				vec3 bent_normal = normal;
 #endif
-				reflection_process(reflection_index, vertex, bent_normal, roughness, ambient_light, specular_light, ambient_accum, reflection_accum);
+				reflection_process(reflection_index, view, vertex, bent_normal, roughness, ambient_light, specular_light, ambient_accum, reflection_accum);
 			}
 		}
 
diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_clustered_inc.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_clustered_inc.glsl
index b700e21543..32ea83397a 100644
--- a/servers/rendering/renderer_rd/shaders/scene_forward_clustered_inc.glsl
+++ b/servers/rendering/renderer_rd/shaders/scene_forward_clustered_inc.glsl
@@ -180,6 +180,7 @@ struct SceneData {
 	// only used for multiview
 	mat4 projection_matrix_view[MAX_VIEWS];
 	mat4 inv_projection_matrix_view[MAX_VIEWS];
+	vec4 eye_offset[MAX_VIEWS];
 
 	vec2 viewport_size;
 	vec2 screen_pixel_size;
@@ -250,7 +251,7 @@ struct SceneData {
 
 	bool pancake_shadows;
 	vec2 taa_jitter;
-	uvec2 pad;
+	uvec2 pad2;
 };
 
 layout(set = 1, binding = 0, std140) uniform SceneDataBlock {
diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl
index 5a308bbd02..c92b29b14a 100644
--- a/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl
+++ b/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl
@@ -869,7 +869,7 @@ void light_process_spot(uint idx, vec3 vertex, vec3 eye_vec, vec3 normal, vec3 v
 			diffuse_light, specular_light);
 }
 
-void reflection_process(uint ref_index, vec3 vertex, vec3 normal, float roughness, vec3 ambient_light, vec3 specular_light, inout vec4 ambient_accum, inout vec4 reflection_accum) {
+void reflection_process(uint ref_index, vec3 view, vec3 vertex, vec3 normal, float roughness, vec3 ambient_light, vec3 specular_light, inout vec4 ambient_accum, inout vec4 reflection_accum) {
 	vec3 box_extents = reflections.data[ref_index].box_extents;
 	vec3 local_pos = (reflections.data[ref_index].local_matrix * vec4(vertex, 1.0)).xyz;
 
@@ -877,7 +877,7 @@ void reflection_process(uint ref_index, vec3 vertex, vec3 normal, float roughnes
 		return;
 	}
 
-	vec3 ref_vec = normalize(reflect(vertex, normal));
+	vec3 ref_vec = normalize(reflect(-view, normal));
 
 	vec3 inner_pos = abs(local_pos / box_extents);
 	float blend = max(inner_pos.x, max(inner_pos.y, inner_pos.z));
diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_mobile.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_mobile.glsl
index e15ebbfc91..cd94908c31 100644
--- a/servers/rendering/renderer_rd/shaders/scene_forward_mobile.glsl
+++ b/servers/rendering/renderer_rd/shaders/scene_forward_mobile.glsl
@@ -586,7 +586,11 @@ void main() {
 
 	//lay out everything, whatever is unused is optimized away anyway
 	vec3 vertex = vertex_interp;
+#ifdef USE_MULTIVIEW
+	vec3 view = -normalize(vertex_interp - scene_data.eye_offset[ViewIndex].xyz);
+#else
 	vec3 view = -normalize(vertex_interp);
+#endif
 	vec3 albedo = vec3(1.0);
 	vec3 backlight = vec3(0.0);
 	vec4 transmittance_color = vec4(0.0);
@@ -1051,7 +1055,7 @@ void main() {
 #else
 			vec3 bent_normal = normal;
 #endif
-			reflection_process(reflection_index, vertex, bent_normal, roughness, ambient_light, specular_light, ambient_accum, reflection_accum);
+			reflection_process(reflection_index, view, vertex, bent_normal, roughness, ambient_light, specular_light, ambient_accum, reflection_accum);
 		}
 
 		if (reflection_accum.a > 0.0) {
diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_mobile_inc.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_mobile_inc.glsl
index dd14a15837..7413d8730a 100644
--- a/servers/rendering/renderer_rd/shaders/scene_forward_mobile_inc.glsl
+++ b/servers/rendering/renderer_rd/shaders/scene_forward_mobile_inc.glsl
@@ -134,6 +134,7 @@ struct SceneData {
 	// only used for multiview
 	highp mat4 projection_matrix_view[MAX_VIEWS];
 	highp mat4 inv_projection_matrix_view[MAX_VIEWS];
+	highp vec4 eye_offset[MAX_VIEWS];
 
 	highp vec2 viewport_size;
 	highp vec2 screen_pixel_size;