Merge branch 'blender-v3.2-release'

# Conflicts:
#	source/blender/draw/engines/eevee/shaders/volumetric_vert.glsl

source/blender/draw/engines/eevee/shaders/volumetric_vert.glsl

@@ -77,3 +77,13 @@ vec3 coordinate_incoming(vec3 P)
 {
   return vec3(0.0);
 }
+
+float attr_load_temperature_post(float attr)
+{
+  return attr;
+}
+
+vec4 attr_load_color_post(vec4 attr)
+{
+  return attr;
+}

source/blender/draw/intern/draw_common.h

@@ -93,7 +93,7 @@ void DRW_curves_free(void);
 /**
  * Add attributes bindings of volume grids to an existing shading group.
  * No draw call is added so the caller can decide how to use the data.
- * \return nullptr if there is something to draw.
+ * \return nullptr if there is nothing to draw.
  */
 struct DRWShadingGroup *DRW_shgroup_volume_create_sub(struct Scene *scene,
                                                       struct Object *ob,

source/blender/draw/intern/draw_volume.cc

@@ -129,12 +129,14 @@ static DRWShadingGroup *drw_volume_object_grids_init(Object *ob,
   volume_infos.temperature_bias = 0.0f;
 
   /* Bind volume grid textures. */
-  int grid_id = 0;
+  int grid_id = 0, grids_len = 0;
   LISTBASE_FOREACH (GPUMaterialAttribute *, attr, attrs) {
     const VolumeGrid *volume_grid = BKE_volume_grid_find_for_read(volume, attr->name);
     const DRWVolumeGrid *drw_grid = (volume_grid) ?
                                         DRW_volume_batch_cache_get_grid(volume, volume_grid) :
                                         nullptr;
+    /* Count number of valid attributes. */
+    grids_len += int(volume_grid != nullptr);
 
     /* Handle 3 cases here:
      * - Grid exists and texture was loaded -> use texture.
@@ -145,7 +147,13 @@ static DRWShadingGroup *drw_volume_object_grids_init(Object *ob,
                                                  grid_default_texture(attr->default_value);
     DRW_shgroup_uniform_texture(grp, attr->input_name, grid_tex);
 
-    copy_m4_m4(volume_infos.grids_xform[grid_id++].ptr(), drw_grid->object_to_texture);
+    copy_m4_m4(volume_infos.grids_xform[grid_id++].ptr(),
+               (drw_grid) ? drw_grid->object_to_texture : g_data.dummy_grid_mat);
+  }
+  /* Render nothing if there is no attribute for the shader to render.
+   * This also avoids an assert caused by the bounding box being zero in size. */
+  if (grids_len == 0) {
+    return nullptr;
   }
 
   volume_infos.push_update();

source/blender/gpu/shaders/material/gpu_shader_material_camera.glsl

@@ -1,6 +1,8 @@
 void camera(out vec3 outview, out float outdepth, out float outdist)
 {
-  outdepth = abs(transform_point(ViewMatrix, g_data.P).z);
-  outdist = distance(g_data.P, cameraPos);
-  outview = normalize(g_data.P - cameraPos);
+  vec3 vP = transform_point(ViewMatrix, g_data.P);
+  vP.z = -vP.z;
+  outdepth = abs(vP.z);
+  outdist = length(vP);
+  outview = normalize(vP);
 }