UDIM: Add support for packing inside .blend files

This completes support for tiled texture packing on the Blender / Cycles
side of things.

Most of these changes fall into one of three categories:
- Updating Image handling code to pack/unpack tiled and multi-view images
- Updating Cycles to handle tiled textures through BlenderImageLoader
- Updating OSL to properly handle textures with multiple slots

Differential Revision: https://developer.blender.org/D14395

5 files changed, 67 insertions, 13 deletions

diff --git a/intern/cycles/scene/image.cpp b/intern/cycles/scene/image.cpp
index 21fde88915e..c61ad1f1d71 100644
--- a/intern/cycles/scene/image.cpp
+++ b/intern/cycles/scene/image.cpp
@@ -117,12 +117,12 @@ void ImageHandle::clear()
   manager = NULL;
 }
 
-bool ImageHandle::empty()
+bool ImageHandle::empty() const
 {
   return tile_slots.empty();
 }
 
-int ImageHandle::num_tiles()
+int ImageHandle::num_tiles() const
 {
   return tile_slots.size();
 }
@@ -154,6 +154,35 @@ int ImageHandle::svm_slot(const int tile_index) const
   return tile_slots[tile_index];
 }
 
+vector<int4> ImageHandle::get_svm_slots() const
+{
+  const size_t num_nodes = divide_up(tile_slots.size(), 2);
+
+  vector<int4> svm_slots;
+  svm_slots.reserve(num_nodes);
+  for (size_t i = 0; i < num_nodes; i++) {
+    int4 node;
+
+    int slot = tile_slots[2 * i];
+    node.x = manager->images[slot]->loader->get_tile_number();
+    node.y = slot;
+
+    if ((2 * i + 1) < tile_slots.size()) {
+      slot = tile_slots[2 * i + 1];
+      node.z = manager->images[slot]->loader->get_tile_number();
+      node.w = slot;
+    }
+    else {
+      node.z = -1;
+      node.w = -1;
+    }
+
+    svm_slots.push_back(node);
+  }
+
+  return svm_slots;
+}
+
 device_texture *ImageHandle::image_memory(const int tile_index) const
 {
   if (tile_index >= tile_slots.size()) {
@@ -266,6 +295,11 @@ ustring ImageLoader::osl_filepath() const
   return ustring();
 }
 
+int ImageLoader::get_tile_number() const
+{
+  return 0;
+}
+
 bool ImageLoader::equals(const ImageLoader *a, const ImageLoader *b)
 {
   if (a == NULL && b == NULL) {
@@ -397,6 +431,19 @@ ImageHandle ImageManager::add_image(ImageLoader *loader,
   return handle;
 }
 
+ImageHandle ImageManager::add_image(const vector<ImageLoader *> &loaders,
+                                    const ImageParams &params)
+{
+  ImageHandle handle;
+  for (ImageLoader *loader : loaders) {
+    const int slot = add_image_slot(loader, params, true);
+    handle.tile_slots.push_back(slot);
+  }
+
+  handle.manager = this;
+  return handle;
+}
+
 int ImageManager::add_image_slot(ImageLoader *loader,
                                  const ImageParams &params,
                                  const bool builtin)
diff --git a/intern/cycles/scene/image.h b/intern/cycles/scene/image.h
index 4d0dee35eca..9edb6a7eaf5 100644
--- a/intern/cycles/scene/image.h
+++ b/intern/cycles/scene/image.h
@@ -112,6 +112,9 @@ class ImageLoader {
   /* Optional for OSL texture cache. */
   virtual ustring osl_filepath() const;
 
+  /* Optional for tiled textures loaded externally. */
+  virtual int get_tile_number() const;
+
   /* Free any memory used for loading metadata and pixels. */
   virtual void cleanup(){};
 
@@ -139,11 +142,12 @@ class ImageHandle {
 
   void clear();
 
-  bool empty();
-  int num_tiles();
+  bool empty() const;
+  int num_tiles() const;
 
   ImageMetaData metadata();
   int svm_slot(const int tile_index = 0) const;
+  vector<int4> get_svm_slots() const;
   device_texture *image_memory(const int tile_index = 0) const;
 
   VDBImageLoader *vdb_loader(const int tile_index = 0) const;
@@ -169,6 +173,7 @@ class ImageManager {
                         const ImageParams &params,
                         const array<int> &tiles);
   ImageHandle add_image(ImageLoader *loader, const ImageParams &params, const bool builtin = true);
+  ImageHandle add_image(const vector<ImageLoader *> &loaders, const ImageParams &params);
 
   void device_update(Device *device, Scene *scene, Progress &progress);
   void device_update_slot(Device *device, Scene *scene, int slot, Progress *progress);
diff --git a/intern/cycles/scene/osl.cpp b/intern/cycles/scene/osl.cpp
index ffa1a2f5623..6698e6e2cce 100644
--- a/intern/cycles/scene/osl.cpp
+++ b/intern/cycles/scene/osl.cpp
@@ -1211,14 +1211,15 @@ void OSLCompiler::parameter_texture(const char *name, ustring filename, ustring
   parameter(name, filename);
 }
 
-void OSLCompiler::parameter_texture(const char *name, int svm_slot)
+void OSLCompiler::parameter_texture(const char *name, const ImageHandle &handle)
 {
   /* Texture loaded through SVM image texture system. We generate a unique
    * name, which ends up being used in OSLRenderServices::get_texture_handle
    * to get handle again. Note that this name must be unique between multiple
    * render sessions as the render services are shared. */
   ustring filename(string_printf("@svm%d", texture_shared_unique_id++).c_str());
-  services->textures.insert(filename, new OSLTextureHandle(OSLTextureHandle::SVM, svm_slot));
+  services->textures.insert(filename,
+                            new OSLTextureHandle(OSLTextureHandle::SVM, handle.get_svm_slots()));
   parameter(name, filename);
 }
 
@@ -1290,7 +1291,7 @@ void OSLCompiler::parameter_texture(const char * /* name */,
 {
 }
 
-void OSLCompiler::parameter_texture(const char * /* name */, int /* svm_slot */)
+void OSLCompiler::parameter_texture(const char * /* name */, const ImageHandle & /*handle*/)
 {
 }
 
diff --git a/intern/cycles/scene/osl.h b/intern/cycles/scene/osl.h
index f0f97dbcaad..bf27069b1b1 100644
--- a/intern/cycles/scene/osl.h
+++ b/intern/cycles/scene/osl.h
@@ -147,7 +147,7 @@ class OSLCompiler {
   void parameter_attribute(const char *name, ustring s);
 
   void parameter_texture(const char *name, ustring filename, ustring colorspace);
-  void parameter_texture(const char *name, int svm_slot);
+  void parameter_texture(const char *name, const ImageHandle &handle);
   void parameter_texture_ies(const char *name, int svm_slot);
 
   ShaderType output_type()
diff --git a/intern/cycles/scene/shader_nodes.cpp b/intern/cycles/scene/shader_nodes.cpp
index 9a61a8a753b..03c152928d5 100644
--- a/intern/cycles/scene/shader_nodes.cpp
+++ b/intern/cycles/scene/shader_nodes.cpp
@@ -453,14 +453,15 @@ void ImageTextureNode::compile(OSLCompiler &compiler)
         "filename", filename, compress_as_srgb ? u_colorspace_raw : known_colorspace);
   }
   else {
-    compiler.parameter_texture("filename", handle.svm_slot());
+    compiler.parameter_texture("filename", handle);
   }
 
   const bool unassociate_alpha = !(ColorSpaceManager::colorspace_is_data(colorspace) ||
                                    alpha_type == IMAGE_ALPHA_CHANNEL_PACKED ||
                                    alpha_type == IMAGE_ALPHA_IGNORE);
   const bool is_tiled = (filename.find("<UDIM>") != string::npos ||
-                         filename.find("<UVTILE>") != string::npos);
+                         filename.find("<UVTILE>") != string::npos) ||
+                        handle.num_tiles() > 1;
 
   compiler.parameter(this, "projection");
   compiler.parameter(this, "projection_blend");
@@ -605,7 +606,7 @@ void EnvironmentTextureNode::compile(OSLCompiler &compiler)
         "filename", filename, compress_as_srgb ? u_colorspace_raw : known_colorspace);
   }
   else {
-    compiler.parameter_texture("filename", handle.svm_slot());
+    compiler.parameter_texture("filename", handle);
   }
 
   compiler.parameter(this, "projection");
@@ -960,7 +961,7 @@ void SkyTextureNode::compile(OSLCompiler &compiler)
   compiler.parameter_array("nishita_data", sunsky.nishita_data, 10);
   /* nishita texture */
   if (sky_type == NODE_SKY_NISHITA) {
-    compiler.parameter_texture("filename", handle.svm_slot());
+    compiler.parameter_texture("filename", handle);
   }
   compiler.add(this, "node_sky_texture");
 }
@@ -1855,7 +1856,7 @@ void PointDensityTextureNode::compile(OSLCompiler &compiler)
       handle = image_manager->add_image(filename.string(), image_params());
     }
 
-    compiler.parameter_texture("filename", handle.svm_slot());
+    compiler.parameter_texture("filename", handle);
     if (space == NODE_TEX_VOXEL_SPACE_WORLD) {
       compiler.parameter("mapping", tfm);
       compiler.parameter("use_mapping", 1);