Cycles: Add command line option for overriding the compute device

The current way of setting the compute device makes sense for local
use, but for headless rendering it it a massive pain to get Cycles
to use the correct device, usually involving entire Python scripts.

Therefore, this patch adds a simple command-line option to Blender
for specifying the type of device that should be used. If the option
is present, the settings in the user preferences and the scene are
ignored, and instead all devices matching the specified type are used.

Differential Revision: https://developer.blender.org/D9086

1 files changed, 9 insertions, 0 deletions

diff --git a/intern/cycles/blender/addon/engine.py b/intern/cycles/blender/addon/engine.py
index 54221d3f1e0..807dcaf7f43 100644
--- a/intern/cycles/blender/addon/engine.py
+++ b/intern/cycles/blender/addon/engine.py
@@ -70,6 +70,11 @@ def _configure_argument_parser():
     parser.add_argument("--cycles-print-stats",
                         help="Print rendering statistics to stderr",
                         action='store_true')
+    parser.add_argument("--cycles-device",
+                        help="Set the device to use for Cycles, overriding user preferences and the scene setting."
+                             "Valid options are 'CPU', 'CUDA', 'OPTIX' or 'OPENCL'."
+                             "Additionally, you can append '+CPU' to any GPU type for hybrid rendering.",
+                        default=None)
     return parser
 
 
@@ -102,6 +107,10 @@ def _parse_command_line():
         import _cycles
         _cycles.enable_print_stats()
 
+    if args.cycles_device:
+        import _cycles
+        _cycles.set_device_override(args.cycles_device)
+
 
 def init():
     import bpy