[Bf-blender-cvs] [5de40f48385] eevee-motionblur-object: EEVEE: Motion Blur: Fix TAA reprojection

[Clément Foucault]

Commit: 5de40f483854f9583a54a808344d0d6e100fb74e
Author: Clément Foucault
Date:   Tue Mar 31 16:45:30 2020 +0200
Branches: eevee-motionblur-object
https://developer.blender.org/rB5de40f483854f9583a54a808344d0d6e100fb74e

EEVEE: Motion Blur: Fix TAA reprojection

We compute the motion vector on the fly based on camera motion.

===================================================================

M	source/blender/draw/engines/eevee/eevee_private.h
M	source/blender/draw/engines/eevee/eevee_temporal_sampling.c
M	source/blender/draw/engines/eevee/shaders/effect_temporal_aa.glsl

===================================================================

diff --git a/source/blender/draw/engines/eevee/eevee_private.h b/source/blender/draw/engines/eevee/eevee_private.h
index b7aa90146b0..89458062215 100644
--- a/source/blender/draw/engines/eevee/eevee_private.h
+++ b/source/blender/draw/engines/eevee/eevee_private.h
@@ -605,7 +605,7 @@ typedef struct EEVEE_EffectsInfo {
   float taa_alpha;
   bool prev_drw_support;
   bool prev_is_navigating;
-  float prev_drw_persmat[4][4];
+  float prev_drw_persmat[4][4]; /* Used for checking view validity and reprojection. */
   struct DRWView *taa_view;
   /* Ambient Occlusion */
   int ao_depth_layer;
diff --git a/source/blender/draw/engines/eevee/eevee_temporal_sampling.c b/source/blender/draw/engines/eevee/eevee_temporal_sampling.c
index 29441a8584b..9b63863d985 100644
--- a/source/blender/draw/engines/eevee/eevee_temporal_sampling.c
+++ b/source/blender/draw/engines/eevee/eevee_temporal_sampling.c
@@ -241,7 +241,6 @@ int EEVEE_temporal_sampling_init(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data
 
     DRW_view_persmat_get(NULL, persmat, false);
     view_is_valid = view_is_valid && compare_m4m4(persmat, effects->prev_drw_persmat, FLT_MIN);
-    copy_m4_m4(effects->prev_drw_persmat, persmat);
 
     /* Prevent ghosting from probe data. */
     view_is_valid = view_is_valid && (effects->prev_drw_support == DRW_state_draw_support()) &&
@@ -283,7 +282,7 @@ void EEVEE_temporal_sampling_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data
   EEVEE_TextureList *txl = vedata->txl;
   EEVEE_EffectsInfo *effects = stl->effects;
 
-  if ((effects->enabled_effects & (EFFECT_TAA | EFFECT_TAA_REPROJECT)) != 0) {
+  if (effects->enabled_effects & EFFECT_TAA) {
     struct GPUShader *sh = EEVEE_shaders_taa_resolve_sh_get(effects->enabled_effects);
 
     DRW_PASS_CREATE(psl->taa_resolve, DRW_STATE_WRITE_COLOR);
@@ -296,9 +295,9 @@ void EEVEE_temporal_sampling_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data
         grp, "renderpass_block", EEVEE_material_default_render_pass_ubo_get(sldata));
 
     if (effects->enabled_effects & EFFECT_TAA_REPROJECT) {
-      // DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
-      // DRW_shgroup_uniform_texture_ref(grp, "velocityBuffer", &effects->velocity_tx);
-      /* TODO FIX */
+      DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
+      DRW_shgroup_uniform_texture_ref(grp, "depthBuffer", &dtxl->depth);
+      DRW_shgroup_uniform_mat4(grp, "prevViewProjectionMatrix", effects->prev_drw_persmat);
     }
     else {
       DRW_shgroup_uniform_float(grp, "alpha", &effects->taa_alpha, 1);
@@ -366,5 +365,7 @@ void EEVEE_temporal_sampling_draw(EEVEE_Data *vedata)
         DRW_viewport_request_redraw();
       }
     }
+
+    DRW_view_persmat_get(NULL, effects->prev_drw_persmat, false);
   }
 }
diff --git a/source/blender/draw/engines/eevee/shaders/effect_temporal_aa.glsl b/source/blender/draw/engines/eevee/shaders/effect_temporal_aa.glsl
index 45c1b48b010..b44645174bd 100644
--- a/source/blender/draw/engines/eevee/shaders/effect_temporal_aa.glsl
+++ b/source/blender/draw/engines/eevee/shaders/effect_temporal_aa.glsl
@@ -1,6 +1,6 @@
 
 uniform sampler2D colorHistoryBuffer;
-uniform sampler2D velocityBuffer;
+uniform mat4 prevViewProjectionMatrix;
 
 out vec4 FragColor;
 
@@ -38,17 +38,19 @@ vec3 clip_to_aabb(vec3 color, vec3 minimum, vec3 maximum, vec3 average)
  */
 void main()
 {
+  vec2 screen_res = vec2(textureSize(colorBuffer, 0).xy);
+  vec2 uv = gl_FragCoord.xy / screen_res;
   ivec2 texel = ivec2(gl_FragCoord.xy);
-  // vec2 motion = texelFetch(velocityBuffer, texel, 0).rg;
-  vec2 motion = vec2(0.5);
-
-  /* Decode from unsigned normalized 16bit texture. */
-  motion = motion * 2.0 - 1.0;
 
   /* Compute pixel position in previous frame. */
-  vec2 screen_res = vec2(textureSize(colorBuffer, 0).xy);
-  vec2 uv = gl_FragCoord.xy / screen_res;
-  vec2 uv_history = uv - motion;
+  float depth = textureLod(depthBuffer, uv, 0.0).r;
+  vec3 pos = get_world_space_from_depth(uv, depth);
+  vec2 uv_history = project_point(prevViewProjectionMatrix, pos).xy * 0.5 + 0.5;
+
+  /* HACK: Reject lookdev spheres from TAA reprojection. */
+  if (depth == 0.0) {
+    uv_history = uv;
+  }
 
   ivec2 texel_history = ivec2(uv_history * screen_res);
   vec4 color_history = textureLod(colorHistoryBuffer, uv_history, 0.0);