1 files changed, 26 insertions, 12 deletions

diff --git a/source/blender/draw/engines/eevee_next/shaders/eevee_velocity_lib.glsl b/source/blender/draw/engines/eevee_next/shaders/eevee_velocity_lib.glsl
index c21456b7a5c..c0a5b976810 100644
--- a/source/blender/draw/engines/eevee_next/shaders/eevee_velocity_lib.glsl
+++ b/source/blender/draw/engines/eevee_next/shaders/eevee_velocity_lib.glsl
@@ -2,8 +2,6 @@
 #pragma BLENDER_REQUIRE(common_view_lib.glsl)
 #pragma BLENDER_REQUIRE(eevee_camera_lib.glsl)
 
-#ifdef VELOCITY_CAMERA
-
 vec4 velocity_pack(vec4 data)
 {
   return data * 0.01;
@@ -14,6 +12,8 @@ vec4 velocity_unpack(vec4 data)
   return data * 100.0;
 }
 
+#ifdef VELOCITY_CAMERA
+
 /**
  * Given a triple of position, compute the previous and next motion vectors.
  * Returns uv space motion vectors in pairs (motion_prev.xy, motion_next.xy).
@@ -24,7 +24,15 @@ vec4 velocity_surface(vec3 P_prv, vec3 P, vec3 P_nxt)
   vec2 prev_uv = project_point(camera_prev.persmat, P_prv).xy;
   vec2 curr_uv = project_point(camera_curr.persmat, P).xy;
   vec2 next_uv = project_point(camera_next.persmat, P_nxt).xy;
-
+  /* Fix issue with perspective division. */
+  if (any(isnan(prev_uv))) {
+    prev_uv = curr_uv;
+  }
+  if (any(isnan(next_uv))) {
+    next_uv = curr_uv;
+  }
+  /* NOTE: We output both vectors in the same direction so we can reuse the same vector
+   * with rgrg swizzle in viewport. */
   vec4 motion = vec4(prev_uv - curr_uv, curr_uv - next_uv);
   /* Convert NDC velocity to UV velocity */
   motion *= 0.5;
@@ -45,7 +53,8 @@ vec4 velocity_background(vec3 vV)
   vec2 prev_uv = project_point(camera_prev.winmat, V).xy;
   vec2 curr_uv = project_point(camera_curr.winmat, V).xy;
   vec2 next_uv = project_point(camera_next.winmat, V).xy;
-
+  /* NOTE: We output both vectors in the same direction so we can reuse the same vector
+   * with rgrg swizzle in viewport. */
   vec4 motion = vec4(prev_uv - curr_uv, curr_uv - next_uv);
   /* Convert NDC velocity to UV velocity */
   motion *= 0.5;
@@ -53,15 +62,8 @@ vec4 velocity_background(vec3 vV)
   return motion;
 }
 
-/**
- * Load and resolve correct velocity as some pixels might still not have correct
- * motion data for performance reasons.
- */
-vec4 velocity_resolve(sampler2D vector_tx, ivec2 texel, float depth)
+vec4 velocity_resolve(vec4 vector, vec2 uv, float depth)
 {
-  vec2 uv = (vec2(texel) + 0.5) / vec2(textureSize(vector_tx, 0).xy);
-  vec4 vector = texelFetch(vector_tx, texel, 0);
-
   if (vector.x == VELOCITY_INVALID) {
     bool is_background = (depth == 1.0);
     if (is_background) {
@@ -78,6 +80,18 @@ vec4 velocity_resolve(sampler2D vector_tx, ivec2 texel, float depth)
   return velocity_unpack(vector);
 }
 
+/**
+ * Load and resolve correct velocity as some pixels might still not have correct
+ * motion data for performance reasons.
+ * Returns motion vector in render UV space.
+ */
+vec4 velocity_resolve(sampler2D vector_tx, ivec2 texel, float depth)
+{
+  vec2 uv = (vec2(texel) + 0.5) / vec2(textureSize(vector_tx, 0).xy);
+  vec4 vector = texelFetch(vector_tx, texel, 0);
+  return velocity_resolve(vector, uv, depth);
+}
+
 #endif
 
 #ifdef MAT_VELOCITY