7 files changed, 67 insertions, 4 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
diff --git a/intern/cycles/blender/blender_device.cpp b/intern/cycles/blender/blender_device.cpp
index fb9ab9e8c97..0293223864d 100644
--- a/intern/cycles/blender/blender_device.cpp
+++ b/intern/cycles/blender/blender_device.cpp
@@ -15,6 +15,7 @@
  */
 
 #include "blender/blender_device.h"
+#include "blender/blender_session.h"
 #include "blender/blender_util.h"
 
 #include "util/util_foreach.h"
@@ -42,6 +43,18 @@ int blender_device_threads(BL::Scene &b_scene)
 
 DeviceInfo blender_device_info(BL::Preferences &b_preferences, BL::Scene &b_scene, bool background)
 {
+  if (BlenderSession::device_override != DEVICE_MASK_ALL) {
+    vector<DeviceInfo> devices = Device::available_devices(BlenderSession::device_override);
+
+    if (devices.empty()) {
+      printf("Found no Cycles device of the specified type, falling back to CPU...\n");
+      return Device::available_devices(DEVICE_MASK_CPU).front();
+    }
+
+    int threads = blender_device_threads(b_scene);
+    return Device::get_multi_device(devices, threads, background);
+  }
+
   PointerRNA cscene = RNA_pointer_get(&b_scene.ptr, "cycles");
 
   /* Default to CPU device. */
diff --git a/intern/cycles/blender/blender_python.cpp b/intern/cycles/blender/blender_python.cpp
index 25c77b74ce3..65337d1ba4f 100644
--- a/intern/cycles/blender/blender_python.cpp
+++ b/intern/cycles/blender/blender_python.cpp
@@ -968,6 +968,44 @@ static PyObject *get_device_types_func(PyObject * /*self*/, PyObject * /*args*/)
   return list;
 }
 
+static PyObject *set_device_override_func(PyObject * /*self*/, PyObject *arg)
+{
+  PyObject *override_string = PyObject_Str(arg);
+  string override = PyUnicode_AsUTF8(override_string);
+  Py_DECREF(override_string);
+
+  bool include_cpu = false;
+  const string cpu_suffix = "+CPU";
+  if (string_endswith(override, cpu_suffix)) {
+    include_cpu = true;
+    override = override.substr(0, override.length() - cpu_suffix.length());
+  }
+
+  if (override == "CPU") {
+    BlenderSession::device_override = DEVICE_MASK_CPU;
+  }
+  else if (override == "OPENCL") {
+    BlenderSession::device_override = DEVICE_MASK_OPENCL;
+  }
+  else if (override == "CUDA") {
+    BlenderSession::device_override = DEVICE_MASK_CUDA;
+  }
+  else if (override == "OPTIX") {
+    BlenderSession::device_override = DEVICE_MASK_OPTIX;
+  }
+  else {
+    printf("\nError: %s is not a valid Cycles device.\n", override.c_str());
+    Py_RETURN_FALSE;
+  }
+
+  if (include_cpu) {
+    BlenderSession::device_override = (DeviceTypeMask)(BlenderSession::device_override |
+                                                       DEVICE_MASK_CPU);
+  }
+
+  Py_RETURN_TRUE;
+}
+
 static PyMethodDef methods[] = {
     {"init", init_func, METH_VARARGS, ""},
     {"exit", exit_func, METH_VARARGS, ""},
@@ -1007,6 +1045,7 @@ static PyMethodDef methods[] = {
 
     /* Compute Device selection */
     {"get_device_types", get_device_types_func, METH_VARARGS, ""},
+    {"set_device_override", set_device_override_func, METH_O, ""},
 
     {NULL, NULL, 0, NULL},
 };
diff --git a/intern/cycles/blender/blender_session.cpp b/intern/cycles/blender/blender_session.cpp
index 8e962f17f56..c2bdec0e53d 100644
--- a/intern/cycles/blender/blender_session.cpp
+++ b/intern/cycles/blender/blender_session.cpp
@@ -47,6 +47,7 @@
 
 CCL_NAMESPACE_BEGIN
 
+DeviceTypeMask BlenderSession::device_override = DEVICE_MASK_ALL;
 bool BlenderSession::headless = false;
 int BlenderSession::num_resumable_chunks = 0;
 int BlenderSession::current_resumable_chunk = 0;
diff --git a/intern/cycles/blender/blender_session.h b/intern/cycles/blender/blender_session.h
index 34e952e312b..68db8a2fb58 100644
--- a/intern/cycles/blender/blender_session.h
+++ b/intern/cycles/blender/blender_session.h
@@ -126,6 +126,7 @@ class BlenderSession {
   /* Global state which is common for all render sessions created from Blender.
    * Usually denotes command line arguments.
    */
+  static DeviceTypeMask device_override;
 
   /* Blender is running from the command line, no windows are shown and some
    * extra render optimization is possible (possible to free draw-only data and
diff --git a/intern/cycles/util/util_string.cpp b/intern/cycles/util/util_string.cpp
index afcca7e0411..4dfebf14923 100644
--- a/intern/cycles/util/util_string.cpp
+++ b/intern/cycles/util/util_string.cpp
@@ -117,14 +117,14 @@ bool string_startswith(const string &s, const char *start)
     return strncmp(s.c_str(), start, len) == 0;
 }
 
-bool string_endswith(const string &s, const char *end)
+bool string_endswith(const string &s, const string &end)
 {
-  size_t len = strlen(end);
+  size_t len = end.length();
 
   if (len > s.size())
     return 0;
   else
-    return strncmp(s.c_str() + s.size() - len, end, len) == 0;
+    return s.compare(s.length() - len, len, end) == 0;
 }
 
 string string_strip(const string &s)
diff --git a/intern/cycles/util/util_string.h b/intern/cycles/util/util_string.h
index ce2d4acdde4..f51aa7111e8 100644
--- a/intern/cycles/util/util_string.h
+++ b/intern/cycles/util/util_string.h
@@ -46,7 +46,7 @@ void string_split(vector<string> &tokens,
                   bool skip_empty_tokens = true);
 void string_replace(string &haystack, const string &needle, const string &other);
 bool string_startswith(const string &s, const char *start);
-bool string_endswith(const string &s, const char *end);
+bool string_endswith(const string &s, const string &end);
 string string_strip(const string &s);
 string string_remove_trademark(const string &s);
 string string_from_bool(const bool var);