Cycles: animation denoising support in the kernel.

This is the internal implementation, not available from the API or
interface yet. The algorithm takes into account past and future frames,
both to get more coherent animation and reduce noise.

Ref D3889.

1 files changed, 49 insertions, 10 deletions

diff --git a/intern/cycles/device/device_denoising.cpp b/intern/cycles/device/device_denoising.cpp
index 724171c3acb..61e0ba47ab8 100644
--- a/intern/cycles/device/device_denoising.cpp
+++ b/intern/cycles/device/device_denoising.cpp
@@ -36,6 +36,7 @@ DenoisingTask::DenoisingTask(Device *device, const DeviceTask &task)
 		pca_threshold = powf(10.0f, lerp(-5.0f, 3.0f, task.denoising_feature_strength));
 	}
 
+	render_buffer.frame_stride = task.frame_stride;
 	render_buffer.pass_stride = task.pass_stride;
 	render_buffer.offset = task.pass_denoising_data;
 
@@ -49,6 +50,12 @@ DenoisingTask::DenoisingTask(Device *device, const DeviceTask &task)
 	tile_info = (TileInfo*) tile_info_mem.alloc(sizeof(TileInfo)/sizeof(int));
 	tile_info->from_render = task.denoising_from_render? 1 : 0;
 
+	tile_info->frames[0] = 0;
+	tile_info->num_frames = min(task.denoising_frames.size() + 1, DENOISE_MAX_FRAMES);
+	for(int i = 1; i < tile_info->num_frames; i++) {
+		tile_info->frames[i] = task.denoising_frames[i-1];
+	}
+
 	write_passes = task.denoising_write_passes;
 	do_filter = task.denoising_do_filter;
 }
@@ -101,16 +108,18 @@ void DenoisingTask::setup_denoising_buffer()
 	rect = rect_expand(rect, radius);
 	rect = rect_clip(rect, make_int4(tile_info->x[0], tile_info->y[0], tile_info->x[3], tile_info->y[3]));
 
-	buffer.use_intensity = write_passes;
+	buffer.use_intensity = write_passes || (tile_info->num_frames > 1);
 	buffer.passes = buffer.use_intensity? 15 : 14;
 	buffer.width = rect.z - rect.x;
 	buffer.stride = align_up(buffer.width, 4);
 	buffer.h = rect.w - rect.y;
 	int alignment_floats = divide_up(device->mem_sub_ptr_alignment(), sizeof(float));
 	buffer.pass_stride = align_up(buffer.stride * buffer.h, alignment_floats);
+	buffer.frame_stride = buffer.pass_stride * buffer.passes;
 	/* Pad the total size by four floats since the SIMD kernels might go a bit over the end. */
-	int mem_size = align_up(buffer.pass_stride * buffer.passes + 4, alignment_floats);
+	int mem_size = align_up(tile_info->num_frames * buffer.frame_stride + 4, alignment_floats);
 	buffer.mem.alloc_to_device(mem_size, false);
+	buffer.use_time = (tile_info->num_frames > 1);
 
 	/* CPUs process shifts sequentially while GPUs process them in parallel. */
 	int num_layers;
@@ -216,6 +225,25 @@ void DenoisingTask::prefilter_color()
 	}
 }
 
+void DenoisingTask::load_buffer()
+{
+	device_ptr null_ptr = (device_ptr) 0;
+
+	int original_offset = render_buffer.offset;
+
+	int num_passes = buffer.use_intensity? 15 : 14;
+	for(int i = 0; i < tile_info->num_frames; i++) {
+		for(int pass = 0; pass < num_passes; pass++) {
+			device_sub_ptr to_pass(buffer.mem, i*buffer.frame_stride + pass*buffer.pass_stride, buffer.pass_stride);
+			bool is_variance = (pass >= 11) && (pass <= 13);
+			functions.get_feature(pass, -1, *to_pass, null_ptr, is_variance? (1.0f / render_buffer.samples) : 1.0f);
+		}
+		render_buffer.offset += render_buffer.frame_stride;
+	}
+
+	render_buffer.offset = original_offset;
+}
+
 void DenoisingTask::write_buffer()
 {
 	reconstruction_state.buffer_params = make_int4(target_buffer.offset,
@@ -259,11 +287,17 @@ void DenoisingTask::reconstruct()
 
 	device_sub_ptr color_ptr    (buffer.mem,  8*buffer.pass_stride, 3*buffer.pass_stride);
 	device_sub_ptr color_var_ptr(buffer.mem, 11*buffer.pass_stride, 3*buffer.pass_stride);
-
-	device_ptr scale_ptr = 0;
-	device_sub_ptr *scale_sub_ptr = NULL;
-	functions.accumulate(*color_ptr, *color_var_ptr, scale_ptr);
-	delete scale_sub_ptr;
+	for(int f = 0; f < tile_info->num_frames; f++) {
+		device_ptr scale_ptr = 0;
+		device_sub_ptr *scale_sub_ptr = NULL;
+		if(tile_info->frames[f] != 0 && (tile_info->num_frames > 1)) {
+			scale_sub_ptr = new device_sub_ptr(buffer.mem, 14*buffer.pass_stride, buffer.pass_stride);
+			scale_ptr = **scale_sub_ptr;
+		}
+
+		functions.accumulate(*color_ptr, *color_var_ptr, scale_ptr, f);
+		delete scale_sub_ptr;
+	}
 	functions.solve(target_buffer.ptr);
 }
 
@@ -276,9 +310,14 @@ void DenoisingTask::run_denoising(RenderTile *tile)
 
 	setup_denoising_buffer();
 
-	prefilter_shadowing();
-	prefilter_features();
-	prefilter_color();
+	if(tile_info->from_render) {
+		prefilter_shadowing();
+		prefilter_features();
+		prefilter_color();
+	}
+	else {
+		load_buffer();
+	}
 
 	if(do_filter) {
 		construct_transform();