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.

release/scripts/startup/bl_ui/properties_render.py

@@ -162,6 +162,35 @@ class RENDER_PT_eevee_motion_blur(RenderButtonsPanel, Panel):
         col.prop(props, "motion_blur_steps", text="Steps")
 
 
+class RENDER_PT_eevee_next_motion_blur(RenderButtonsPanel, Panel):
+    bl_label = "Motion Blur"
+    bl_options = {'DEFAULT_CLOSED'}
+    COMPAT_ENGINES = {'BLENDER_EEVEE_NEXT'}
+
+    @classmethod
+    def poll(cls, context):
+        return (context.engine in cls.COMPAT_ENGINES)
+
+    def draw_header(self, context):
+        scene = context.scene
+        props = scene.eevee
+        self.layout.prop(props, "use_motion_blur", text="")
+
+    def draw(self, context):
+        layout = self.layout
+        layout.use_property_split = True
+        scene = context.scene
+        props = scene.eevee
+
+        layout.active = props.use_motion_blur
+        col = layout.column()
+        col.prop(props, "motion_blur_position", text="Position")
+        col.prop(props, "motion_blur_shutter")
+        col.separator()
+        col.prop(props, "motion_blur_depth_scale")
+        col.prop(props, "motion_blur_steps", text="Steps")
+
+
 class RENDER_PT_eevee_depth_of_field(RenderButtonsPanel, Panel):
     bl_label = "Depth of Field"
     bl_options = {'DEFAULT_CLOSED'}
@@ -756,6 +785,7 @@ classes = (
     RENDER_PT_eevee_film,
 
     RENDER_PT_eevee_next_sampling,
+    RENDER_PT_eevee_next_motion_blur,
     RENDER_PT_eevee_next_film,
 
     RENDER_PT_gpencil,