EEVEE-Next: Motion Blur new implementation

The new implementation leverage compute shaders to reduce the
number of passes and complexity.

The max blur amount is now detected automatically, replacing the property
in the render panel by a simple checkbox.

The dilation algorithm has also been rewritten from scratch into a 1 pass
algorithm that does the dilation more efficiently and more precisely.

Some differences with the old implementation can be observed in areas with
complex motion.

1 files changed, 11 insertions, 2 deletions

diff --git a/source/blender/draw/engines/eevee_next/eevee_film.cc b/source/blender/draw/engines/eevee_next/eevee_film.cc
index 608bf31335c..60e5f95d803 100644
--- a/source/blender/draw/engines/eevee_next/eevee_film.cc
+++ b/source/blender/draw/engines/eevee_next/eevee_film.cc
@@ -214,6 +214,11 @@ void Film::init(const int2 &extent, const rcti *output_rect)
     /* Filter obsolete passes. */
     render_passes &= ~(EEVEE_RENDER_PASS_UNUSED_8 | EEVEE_RENDER_PASS_BLOOM);
 
+    if (scene_eevee.flag & SCE_EEVEE_MOTION_BLUR_ENABLED) {
+      /* Disable motion vector pass if motion blur is enabled. */
+      render_passes &= ~EEVEE_RENDER_PASS_VECTOR;
+    }
+
     /* TODO(@fclem): Can't we rely on depsgraph update notification? */
     if (assign_if_different(enabled_passes_, render_passes)) {
       sampling.reset();
@@ -381,7 +386,7 @@ void Film::sync()
   DRW_shgroup_uniform_block_ref(grp, "camera_curr", &(*velocity.camera_steps[STEP_CURRENT]));
   DRW_shgroup_uniform_block_ref(grp, "camera_next", &(*velocity.camera_steps[step_next]));
   DRW_shgroup_uniform_texture_ref(grp, "depth_tx", &rbuffers.depth_tx);
-  DRW_shgroup_uniform_texture_ref(grp, "combined_tx", &rbuffers.combined_tx);
+  DRW_shgroup_uniform_texture_ref(grp, "combined_tx", &combined_final_tx_);
   DRW_shgroup_uniform_texture_ref(grp, "normal_tx", &rbuffers.normal_tx);
   DRW_shgroup_uniform_texture_ref(grp, "vector_tx", &rbuffers.vector_tx);
   DRW_shgroup_uniform_texture_ref(grp, "diffuse_light_tx", &rbuffers.diffuse_light_tx);
@@ -540,7 +545,7 @@ void Film::update_sample_table()
   }
 }
 
-void Film::accumulate(const DRWView *view)
+void Film::accumulate(const DRWView *view, GPUTexture *combined_final_tx)
 {
   if (inst_.is_viewport()) {
     DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get();
@@ -556,6 +561,8 @@ void Film::accumulate(const DRWView *view)
 
   update_sample_table();
 
+  combined_final_tx_ = combined_final_tx;
+
   /* Need to update the static references as there could have change from a previous swap. */
   weight_src_tx_ = weight_tx_.current();
   weight_dst_tx_ = weight_tx_.next();
@@ -588,6 +595,8 @@ void Film::display()
   GPU_framebuffer_bind(dfbl->default_fb);
   GPU_framebuffer_viewport_set(dfbl->default_fb, UNPACK2(data_.offset), UNPACK2(data_.extent));
 
+  combined_final_tx_ = inst_.render_buffers.combined_tx;
+
   /* Need to update the static references as there could have change from a previous swap. */
   weight_src_tx_ = weight_tx_.current();
   weight_dst_tx_ = weight_tx_.next();