Cycles: Expose "Use MetalRT" checkbox

For curve-heavy scenes, memory consumption regressed when we switched from MetalRT to bvh2. Allow users to opt in to MetalRT to workaround this.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D14071

intern/cycles/blender/addon/properties.py

@@ -1374,6 +1374,12 @@ class CyclesPreferences(bpy.types.AddonPreferences):
         default=False,
     )
 
+    use_metalrt: BoolProperty(
+        name="MetalRT (Experimental)",
+        description="MetalRT for ray tracing uses less memory for scenes which use curves extensively, and can give better performance in specific cases. However this support is experimental and some scenes may render incorrectly",
+        default=False,
+    )
+
     def find_existing_device_entry(self, device):
         for device_entry in self.devices:
             if device_entry.id == device[2] and device_entry.type == device[1]:
@@ -1519,6 +1525,12 @@ class CyclesPreferences(bpy.types.AddonPreferences):
             row.use_property_split = True
             row.prop(self, "peer_memory")
 
+        if compute_device_type == 'METAL':
+            row = layout.row()
+            row.use_property_split = True
+            row.prop(self, "use_metalrt")
+
+
     def draw(self, context):
         self.draw_impl(self.layout, context)
 

intern/cycles/blender/device.cpp

@@ -118,6 +118,10 @@ DeviceInfo blender_device_info(BL::Preferences &b_preferences, BL::Scene &b_scen
     device.has_peer_memory = false;
   }
 
+  if (get_boolean(cpreferences, "use_metalrt")) {
+    device.use_metalrt = true;
+  }
+
   return device;
 }
 

intern/cycles/device/device.cpp

@@ -328,6 +328,7 @@ DeviceInfo Device::get_multi_device(const vector<DeviceInfo> &subdevices,
   info.has_osl = true;
   info.has_profiling = true;
   info.has_peer_memory = false;
+  info.use_metalrt = false;
   info.denoisers = DENOISER_ALL;
 
   foreach (const DeviceInfo &device, subdevices) {
@@ -374,6 +375,7 @@ DeviceInfo Device::get_multi_device(const vector<DeviceInfo> &subdevices,
     info.has_osl &= device.has_osl;
     info.has_profiling &= device.has_profiling;
     info.has_peer_memory |= device.has_peer_memory;
+    info.use_metalrt |= device.use_metalrt;
     info.denoisers &= device.denoisers;
   }
 

intern/cycles/device/device.h

@@ -79,6 +79,7 @@ class DeviceInfo {
   bool has_profiling;         /* Supports runtime collection of profiling info. */
   bool has_peer_memory;       /* GPU has P2P access to memory of another GPU. */
   bool has_gpu_queue;         /* Device supports GPU queue. */
+  bool use_metalrt;           /* Use MetalRT to accelerate ray queries (Metal only). */
   DenoiserTypeMask denoisers; /* Supported denoiser types. */
   int cpu_threads;
   vector<DeviceInfo> multi_devices;
@@ -96,6 +97,7 @@ class DeviceInfo {
     has_profiling = false;
     has_peer_memory = false;
     has_gpu_queue = false;
+    use_metalrt = false;
     denoisers = DENOISER_NONE;
   }
 

intern/cycles/device/metal/device_impl.mm

@@ -100,6 +100,7 @@ MetalDevice::MetalDevice(const DeviceInfo &info, Stats &stats, Profiler &profile
     }
   }
 
+  use_metalrt = info.use_metalrt;
   if (auto metalrt = getenv("CYCLES_METALRT")) {
     use_metalrt = (atoi(metalrt) != 0);
   }