Fixing artifacts in SSR

1 files changed, 25 insertions, 9 deletions

diff --git a/servers/rendering/renderer_rd/shaders/effects/screen_space_reflection.glsl b/servers/rendering/renderer_rd/shaders/effects/screen_space_reflection.glsl
index 9f86643e52..9d8294a7da 100644
--- a/servers/rendering/renderer_rd/shaders/effects/screen_space_reflection.glsl
+++ b/servers/rendering/renderer_rd/shaders/effects/screen_space_reflection.glsl
@@ -121,7 +121,7 @@ void main() {
 
 	// clip z and w advance to line advance
 	vec2 line_advance = normalize(line_dir); // down to pixel
-	float step_size = length(line_advance) / length(line_dir);
+	float step_size = 1.0 / length(line_dir);
 	float z_advance = z_dir * step_size; // adapt z advance to line advance
 	float w_advance = w_dir * step_size; // adapt w advance to line advance
 
@@ -139,6 +139,14 @@ void main() {
 	float depth;
 	vec2 prev_pos = pos;
 
+	if (ivec2(pos + line_advance - 0.5) == ssC) {
+		// It is possible for rounding to cause our first pixel to check to be the pixel we're reflecting.
+		// Make sure we skip it
+		pos += line_advance;
+		z += z_advance;
+		w += w_advance;
+	}
+
 	bool found = false;
 
 	float steps_taken = 0.0;
@@ -149,8 +157,8 @@ void main() {
 		w += w_advance;
 
 		// convert to linear depth
-
-		depth = imageLoad(source_depth, ivec2(pos - 0.5)).r;
+		ivec2 test_pos = ivec2(pos - 0.5);
+		depth = imageLoad(source_depth, test_pos).r;
 		if (sc_multiview) {
 			depth = depth * 2.0 - 1.0;
 			depth = 2.0 * params.camera_z_near * params.camera_z_far / (params.camera_z_far + params.camera_z_near - depth * (params.camera_z_far - params.camera_z_near));
@@ -161,13 +169,21 @@ void main() {
 		z_to = z / w;
 
 		if (depth > z_to) {
-			// if depth was surpassed
-			if (depth <= max(z_to, z_from) + params.depth_tolerance && -depth < params.camera_z_far * 0.95) {
-				// check the depth tolerance and far clip
-				// check that normal is valid
-				found = true;
+			// Test if our ray is hitting the "right" side of the surface, if not we're likely self reflecting and should skip.
+			vec4 test_normal_roughness = imageLoad(source_normal_roughness, test_pos);
+			vec3 test_normal = test_normal_roughness.xyz * 2.0 - 1.0;
+			test_normal = normalize(test_normal);
+			test_normal.y = -test_normal.y; //because this code reads flipped
+
+			if (dot(ray_dir, test_normal) < 0.001) {
+				// if depth was surpassed
+				if (depth <= max(z_to, z_from) + params.depth_tolerance && -depth < params.camera_z_far * 0.95) {
+					// check the depth tolerance and far clip
+					// check that normal is valid
+					found = true;
+				}
+				break;
 			}
-			break;
 		}
 
 		steps_taken += 1.0;