Tune TAA disocclusion scale to avoid rejecting all samples during motion.

servers/rendering/renderer_rd/effects/taa.cpp

@@ -62,8 +62,8 @@ void TAA::resolve(RID p_frame, RID p_temp, RID p_depth, RID p_velocity, RID p_pr
 	memset(&push_constant, 0, sizeof(TAAResolvePushConstant));
 	push_constant.resolution_width = p_resolution.width;
 	push_constant.resolution_height = p_resolution.height;
-	push_constant.disocclusion_threshold = 0.025f;
-	push_constant.disocclusion_scale = 10.0f;
+	push_constant.disocclusion_threshold = 2.5f; // If velocity changes by less than this amount of texels we can retain the accumulation buffer.
+	push_constant.disocclusion_scale = 0.01f; // Scale the weight of this pixel calculated as (change in velocity - threshold) * scale.
 
 	RD::ComputeListID compute_list = RD::get_singleton()->compute_list_begin();
 	RD::get_singleton()->compute_list_bind_compute_pipeline(compute_list, pipeline);

servers/rendering/renderer_rd/shaders/effects/taa_resolve.glsl

@@ -307,6 +307,8 @@ float luminance(vec3 color) {
 	return max(dot(color, lumCoeff), 0.0001f);
 }
 
+// This is "velocity disocclusion" as described by https://www.elopezr.com/temporal-aa-and-the-quest-for-the-holy-trail/.
+// We use texel space, so our scale and threshold differ.
 float get_factor_disocclusion(vec2 uv_reprojected, vec2 velocity) {
 	vec2 velocity_previous = imageLoad(last_velocity_buffer, ivec2(uv_reprojected * params.resolution)).xy;
 	vec2 velocity_texels = velocity * params.resolution;
@@ -336,7 +338,7 @@ vec3 temporal_antialiasing(uvec2 pos_group_top_left, uvec2 pos_group, uvec2 pos_
 	// Compute blend factor
 	float blend_factor = RPC_16; // We want to be able to accumulate as many jitter samples as we generated, that is, 16.
 	{
-		// If re-projected UV is out of screen, converge to current color immediatel
+		// If re-projected UV is out of screen, converge to current color immediately.
 		float factor_screen = any(lessThan(uv_reprojected, vec2(0.0))) || any(greaterThan(uv_reprojected, vec2(1.0))) ? 1.0 : 0.0;
 
 		// Increase blend factor when there is disocclusion (fixes a lot of the remaining ghosting).