Cycles: add Optix device backend

This uses hardware-accelerated raytracing on NVIDIA RTX graphics cards.

It is still currently experimental. Most features are supported, but a few
are still missing like baking, branched path tracing and using CPU memory.
https://wiki.blender.org/wiki/Reference/Release_Notes/2.81/Cycles#NVIDIA_RTX

For building with Optix support, the Optix SDK must be installed. See here for
build instructions:
https://wiki.blender.org/wiki/Building_Blender/CUDA

Differential Revision: https://developer.blender.org/D5363

1 files changed, 31 insertions, 15 deletions

diff --git a/intern/cycles/blender/addon/properties.py b/intern/cycles/blender/addon/properties.py
index 93f8f76cd6a..8623b38a271 100644
--- a/intern/cycles/blender/addon/properties.py
+++ b/intern/cycles/blender/addon/properties.py
@@ -137,6 +137,7 @@ enum_world_mis = (
 enum_device_type = (
     ('CPU', "CPU", "CPU", 0),
     ('CUDA', "CUDA", "CUDA", 1),
+    ('OPTIX', "OptiX", "OptiX", 3),
     ('OPENCL', "OpenCL", "OpenCL", 2)
 )
 
@@ -740,6 +741,8 @@ class CyclesRenderSettings(bpy.types.PropertyGroup):
     debug_use_cuda_adaptive_compile: BoolProperty(name="Adaptive Compile", default=False)
     debug_use_cuda_split_kernel: BoolProperty(name="Split Kernel", default=False)
 
+    debug_optix_cuda_streams: IntProperty(name="CUDA Streams", default=1, min=1)
+
     debug_opencl_kernel_type: EnumProperty(
         name="OpenCL Kernel Type",
         default='DEFAULT',
@@ -1400,10 +1403,12 @@ class CyclesPreferences(bpy.types.AddonPreferences):
 
     def get_device_types(self, context):
         import _cycles
-        has_cuda, has_opencl = _cycles.get_device_types()
+        has_cuda, has_optix, has_opencl = _cycles.get_device_types()
         list = [('NONE', "None", "Don't use compute device", 0)]
         if has_cuda:
             list.append(('CUDA', "CUDA", "Use CUDA for GPU acceleration", 1))
+        if has_optix:
+            list.append(('OPTIX', "OptiX", "Use OptiX for GPU acceleration", 3))
         if has_opencl:
             list.append(('OPENCL', "OpenCL", "Use OpenCL for GPU acceleration", 2))
         return list
@@ -1424,7 +1429,7 @@ class CyclesPreferences(bpy.types.AddonPreferences):
 
     def update_device_entries(self, device_list):
         for device in device_list:
-            if not device[1] in {'CUDA', 'OPENCL', 'CPU'}:
+            if not device[1] in {'CUDA', 'OPTIX', 'OPENCL', 'CPU'}:
                 continue
             # Try to find existing Device entry
             entry = self.find_existing_device_entry(device)
@@ -1439,8 +1444,8 @@ class CyclesPreferences(bpy.types.AddonPreferences):
                 # Update name in case it changed
                 entry.name = device[0]
 
-    # Gets all devices types by default.
-    def get_devices(self, compute_device_type=''):
+    # Gets all devices types for a compute device type.
+    def get_devices_for_type(self, compute_device_type):
         import _cycles
         # Layout of the device tuples: (Name, Type, Persistent ID)
         device_list = _cycles.available_devices(compute_device_type)
@@ -1449,20 +1454,23 @@ class CyclesPreferences(bpy.types.AddonPreferences):
         # hold pointers to a resized array.
         self.update_device_entries(device_list)
         # Sort entries into lists
-        cuda_devices = []
-        opencl_devices = []
+        devices = []
         cpu_devices = []
         for device in device_list:
             entry = self.find_existing_device_entry(device)
-            if entry.type == 'CUDA':
-                cuda_devices.append(entry)
-            elif entry.type == 'OPENCL':
-                opencl_devices.append(entry)
+            if entry.type == compute_device_type:
+                devices.append(entry)
             elif entry.type == 'CPU':
                 cpu_devices.append(entry)
         # Extend all GPU devices with CPU.
-        cuda_devices.extend(cpu_devices)
-        opencl_devices.extend(cpu_devices)
+        if compute_device_type in ('CUDA', 'OPENCL'):
+            devices.extend(cpu_devices)
+        return devices
+
+    # For backwards compatibility, only has CUDA and OpenCL.
+    def get_devices(self, compute_device_type=''):
+        cuda_devices = self.get_devices_for_type('CUDA')
+        opencl_devices = self.get_devices_for_type('OPENCL')
         return cuda_devices, opencl_devices
 
     def get_num_gpu_devices(self):
@@ -1498,16 +1506,24 @@ class CyclesPreferences(bpy.types.AddonPreferences):
         for device in devices:
             box.prop(device, "use", text=device.name)
 
+        if device_type == 'OPTIX':
+            col = box.column(align=True)
+            col.label(text="OptiX support is experimental", icon='INFO')
+            col.label(text="Not all Cycles features are supported yet", icon='BLANK1')
+
+
     def draw_impl(self, layout, context):
         row = layout.row()
         row.prop(self, "compute_device_type", expand=True)
 
-        cuda_devices, opencl_devices = self.get_devices(self.compute_device_type)
+        devices = self.get_devices_for_type(self.compute_device_type)
         row = layout.row()
         if self.compute_device_type == 'CUDA':
-            self._draw_devices(row, 'CUDA', cuda_devices)
+            self._draw_devices(row, 'CUDA', devices)
+        elif self.compute_device_type == 'OPTIX':
+            self._draw_devices(row, 'OPTIX', devices)
         elif self.compute_device_type == 'OPENCL':
-            self._draw_devices(row, 'OPENCL', opencl_devices)
+            self._draw_devices(row, 'OPENCL', devices)
 
     def draw(self, context):
         self.draw_impl(self.layout, context)