Fix T74393: Cycles crashes when both OSL and Optix Denoising are enabled

Enabling viewport denoising causes Cycles to use a multi-device, which always returned NULL when
asked for OSL memory and would subsequently crash. This fixes that by returning the correct OSL
memory pointer from the CPU device in the special viewport denoising multi-device.

1 files changed, 8 insertions, 0 deletions

diff --git a/intern/cycles/device/device_multi.cpp b/intern/cycles/device/device_multi.cpp
index 0044610eeb4..631c4169e2e 100644
--- a/intern/cycles/device/device_multi.cpp
+++ b/intern/cycles/device/device_multi.cpp
@@ -183,6 +183,14 @@ class MultiDevice : public Device {
     return true;
   }
 
+  virtual void *osl_memory()
+  {
+    if (devices.size() > 1) {
+      return NULL;
+    }
+    return devices.front().device->osl_memory();
+  }
+
   void mem_alloc(device_memory &mem)
   {
     device_ptr key = unique_key++;