Fix T55436: crash with point density and shader tweaking.

With copy-on-write we can no longer assumes the point density data is
available after Cycles synchronization with Blender data is done. So
force it to be loaded earlier, even if it's not great for interactivity.

7 files changed, 71 insertions, 18 deletions

diff --git a/intern/cycles/blender/blender_session.cpp b/intern/cycles/blender/blender_session.cpp
index 7a9d411b9bb..eec13d04d7d 100644
--- a/intern/cycles/blender/blender_session.cpp
+++ b/intern/cycles/blender/blender_session.cpp
@@ -454,6 +454,7 @@ void BlenderSession::render(BL::Depsgraph& b_depsgraph_)
 						b_camera_override,
 						width, height,
 						&python_thread_state);
+		builtin_images_load();
 
 		/* Make sure all views have different noise patterns. - hardcoded value just to make it random */
 		if(view_index != 0) {
@@ -614,6 +615,7 @@ void BlenderSession::bake(BL::Depsgraph& b_depsgraph_,
 						b_camera_override,
 						width, height,
 						&python_thread_state);
+		builtin_images_load();
 	}
 
 	BakeData *bake_data = NULL;
@@ -803,6 +805,8 @@ void BlenderSession::synchronize(BL::Depsgraph& b_depsgraph_)
 	else
 		sync->sync_camera(b_render, b_camera_override, width, height, "");
 
+	builtin_images_load();
+
 	/* unlock */
 	session->scene->mutex.unlock();
 
@@ -1327,6 +1331,16 @@ bool BlenderSession::builtin_image_float_pixels(const string &builtin_name,
 	return false;
 }
 
+void BlenderSession::builtin_images_load()
+{
+	/* Force builtin images to be loaded along with Blender data sync. This
+	 * is needed because we may be reading from depsgraph evaluated data which
+	 * can be freed by Blender before Cycles reads it. */
+	ImageManager *manager = session->scene->image_manager;
+	Device *device = session->device;
+	manager->device_load_builtin(device, session->scene, session->progress);
+}
+
 void BlenderSession::update_resumable_tile_manager(int num_samples)
 {
 	const int num_resumable_chunks = BlenderSession::num_resumable_chunks,
diff --git a/intern/cycles/blender/blender_session.h b/intern/cycles/blender/blender_session.h
index aecb304c270..1d727e416a0 100644
--- a/intern/cycles/blender/blender_session.h
+++ b/intern/cycles/blender/blender_session.h
@@ -166,6 +166,7 @@ protected:
 	                                float *pixels,
 	                                const size_t pixels_size,
 	                                const bool free_cache);
+	void builtin_images_load();
 
 	/* Update tile manager to reflect resumable render settings. */
 	void update_resumable_tile_manager(int num_samples);
diff --git a/intern/cycles/blender/blender_shader.cpp b/intern/cycles/blender/blender_shader.cpp
index 740416e3a8a..f9ba8a6e6b7 100644
--- a/intern/cycles/blender/blender_shader.cpp
+++ b/intern/cycles/blender/blender_shader.cpp
@@ -862,9 +862,11 @@ static ShaderNode *add_node(Scene *scene,
 		point_density->space = (NodeTexVoxelSpace)b_point_density_node.space();
 		point_density->interpolation = get_image_interpolation(b_point_density_node);
 		point_density->builtin_data = b_point_density_node.ptr.data;
+		point_density->image_manager = scene->image_manager;
 
 		/* TODO(sergey): Use more proper update flag. */
 		if(true) {
+			point_density->add_image();
 			b_point_density_node.cache_point_density(b_depsgraph);
 			scene->image_manager->tag_reload_image(
 			        point_density->filename.string(),
diff --git a/intern/cycles/render/image.cpp b/intern/cycles/render/image.cpp
index 9c5e32e8219..6867ea95d63 100644
--- a/intern/cycles/render/image.cpp
+++ b/intern/cycles/render/image.cpp
@@ -943,6 +943,39 @@ void ImageManager::device_update_slot(Device *device,
 	}
 }
 
+void ImageManager::device_load_builtin(Device *device,
+                                       Scene *scene,
+                                       Progress& progress)
+{
+	/* Load only builtin images, Blender needs this to load evaluated
+	 * scene data from depsgraph before it is freed. */
+	if(!need_update) {
+		return;
+	}
+
+	TaskPool pool;
+	for(int type = 0; type < IMAGE_DATA_NUM_TYPES; type++) {
+		for(size_t slot = 0; slot < images[type].size(); slot++) {
+			if(!images[type][slot])
+				continue;
+
+			if(images[type][slot]->need_load) {
+				if(images[type][slot]->builtin_data) {
+					pool.push(function_bind(&ImageManager::device_load_image,
+					                        this,
+					                        device,
+					                        scene,
+					                        (ImageDataType)type,
+					                        slot,
+					                        &progress));
+				}
+			}
+		}
+	}
+
+	pool.wait_work();
+}
+
 void ImageManager::device_free_builtin(Device *device)
 {
 	for(int type = 0; type < IMAGE_DATA_NUM_TYPES; type++) {
diff --git a/intern/cycles/render/image.h b/intern/cycles/render/image.h
index 5391490d993..66f929aa03a 100644
--- a/intern/cycles/render/image.h
+++ b/intern/cycles/render/image.h
@@ -80,6 +80,10 @@ public:
 	                        int flat_slot,
 	                        Progress *progress);
 	void device_free(Device *device);
+
+	void device_load_builtin(Device *device,
+	                         Scene *scene,
+	                         Progress& progress);
 	void device_free_builtin(Device *device);
 
 	void set_osl_texture_system(void *texture_system);
diff --git a/intern/cycles/render/nodes.cpp b/intern/cycles/render/nodes.cpp
index 3dad4d1a346..3a531f87c10 100644
--- a/intern/cycles/render/nodes.cpp
+++ b/intern/cycles/render/nodes.cpp
@@ -1488,6 +1488,19 @@ void PointDensityTextureNode::attributes(Shader *shader,
 	ShaderNode::attributes(shader, attributes);
 }
 
+void PointDensityTextureNode::add_image()
+{
+	if(slot == -1) {
+		ImageMetaData metadata;
+		slot = image_manager->add_image(filename.string(), builtin_data,
+		                                false, 0,
+		                                interpolation,
+		                                EXTENSION_CLIP,
+		                                true,
+		                                metadata);
+	}
+}
+
 void PointDensityTextureNode::compile(SVMCompiler& compiler)
 {
 	ShaderInput *vector_in = input("Vector");
@@ -1500,15 +1513,7 @@ void PointDensityTextureNode::compile(SVMCompiler& compiler)
 	image_manager = compiler.image_manager;
 
 	if(use_density || use_color) {
-		if(slot == -1) {
-			ImageMetaData metadata;
-			slot = image_manager->add_image(filename.string(), builtin_data,
-			                                false, 0,
-			                                interpolation,
-			                                EXTENSION_CLIP,
-			                                true,
-			                                metadata);
-		}
+		add_image();
 
 		if(slot != -1) {
 			compiler.stack_assign(vector_in);
@@ -1551,15 +1556,7 @@ void PointDensityTextureNode::compile(OSLCompiler& compiler)
 	image_manager = compiler.image_manager;
 
 	if(use_density || use_color) {
-		if(slot == -1) {
-			ImageMetaData metadata;
-			slot = image_manager->add_image(filename.string(), builtin_data,
-			                                false, 0,
-			                                interpolation,
-			                                EXTENSION_CLIP,
-			                                true,
-			                                metadata);
-		}
+		add_image();
 
 		if(slot != -1) {
 			compiler.parameter("filename", string_printf("@i%d", slot).c_str());
diff --git a/intern/cycles/render/nodes.h b/intern/cycles/render/nodes.h
index 35a7df690c3..d1c7c9176e1 100644
--- a/intern/cycles/render/nodes.h
+++ b/intern/cycles/render/nodes.h
@@ -265,6 +265,8 @@ public:
 	bool has_spatial_varying() { return true; }
 	bool has_object_dependency() { return true; }
 
+	void add_image();
+
 	ustring filename;
 	NodeTexVoxelSpace space;
 	InterpolationType interpolation;