Cycles: merge of cycles-x branch, a major update to the renderer

This includes much improved GPU rendering performance, viewport interactivity,
new shadow catcher, revamped sampling settings, subsurface scattering anisotropy,
new GPU volume sampling, improved PMJ sampling pattern, and more.

Some features have also been removed or changed, breaking backwards compatibility.
Including the removal of the OpenCL backend, for which alternatives are under
development.

Release notes and code docs:
https://wiki.blender.org/wiki/Reference/Release_Notes/3.0/Cycles
https://wiki.blender.org/wiki/Source/Render/Cycles

Credits:
* Sergey Sharybin
* Brecht Van Lommel
* Patrick Mours (OptiX backend)
* Christophe Hery (subsurface scattering anisotropy)
* William Leeson (PMJ sampling pattern)
* Alaska (various fixes and tweaks)
* Thomas Dinges (various fixes)

For the full commit history, see the cycles-x branch. This squashes together
all the changes since intermediate changes would often fail building or tests.

Ref T87839, T87837, T87836
Fixes T90734, T89353, T80267, T80267, T77185, T69800

1 files changed, 106 insertions, 0 deletions

diff --git a/intern/cycles/integrator/denoiser_device.cpp b/intern/cycles/integrator/denoiser_device.cpp
new file mode 100644
index 00000000000..8088cfd7800
--- /dev/null
+++ b/intern/cycles/integrator/denoiser_device.cpp
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2011-2021 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "integrator/denoiser_device.h"
+
+#include "device/device.h"
+#include "device/device_denoise.h"
+#include "device/device_memory.h"
+#include "device/device_queue.h"
+#include "render/buffers.h"
+#include "util/util_logging.h"
+#include "util/util_progress.h"
+
+CCL_NAMESPACE_BEGIN
+
+DeviceDenoiser::DeviceDenoiser(Device *path_trace_device, const DenoiseParams &params)
+    : Denoiser(path_trace_device, params)
+{
+}
+
+DeviceDenoiser::~DeviceDenoiser()
+{
+  /* Explicit implementation, to allow forward declaration of Device in the header. */
+}
+
+bool DeviceDenoiser::denoise_buffer(const BufferParams &buffer_params,
+                                    RenderBuffers *render_buffers,
+                                    const int num_samples,
+                                    bool allow_inplace_modification)
+{
+  Device *denoiser_device = get_denoiser_device();
+  if (!denoiser_device) {
+    return false;
+  }
+
+  DeviceDenoiseTask task;
+  task.params = params_;
+  task.num_samples = num_samples;
+  task.buffer_params = buffer_params;
+  task.allow_inplace_modification = allow_inplace_modification;
+
+  RenderBuffers local_render_buffers(denoiser_device);
+  bool local_buffer_used = false;
+
+  if (denoiser_device == render_buffers->buffer.device) {
+    /* The device can access an existing buffer pointer. */
+    local_buffer_used = false;
+    task.render_buffers = render_buffers;
+  }
+  else {
+    VLOG(3) << "Creating temporary buffer on denoiser device.";
+
+    DeviceQueue *queue = denoiser_device->get_denoise_queue();
+
+    /* Create buffer which is available by the device used by denoiser. */
+
+    /* TODO(sergey): Optimize data transfers. For example, only copy denoising related passes,
+     * ignoring other light ad data passes. */
+
+    local_buffer_used = true;
+
+    render_buffers->copy_from_device();
+
+    local_render_buffers.reset(buffer_params);
+
+    /* NOTE: The local buffer is allocated for an exact size of the effective render size, while
+     * the input render buffer is allcoated for the lowest resolution divider possible. So it is
+     * important to only copy actually needed part of the input buffer. */
+    memcpy(local_render_buffers.buffer.data(),
+           render_buffers->buffer.data(),
+           sizeof(float) * local_render_buffers.buffer.size());
+
+    queue->copy_to_device(local_render_buffers.buffer);
+
+    task.render_buffers = &local_render_buffers;
+    task.allow_inplace_modification = true;
+  }
+
+  const bool denoise_result = denoiser_device->denoise_buffer(task);
+
+  if (local_buffer_used) {
+    local_render_buffers.copy_from_device();
+
+    render_buffers_host_copy_denoised(
+        render_buffers, buffer_params, &local_render_buffers, local_render_buffers.params);
+
+    render_buffers->copy_to_device();
+  }
+
+  return denoise_result;
+}
+
+CCL_NAMESPACE_END