blender: Hook up background shader

Blender 3.6 started crashing in the blender UI code after these changes,
no idea why, I'll go test on 4.0 on my desktop.

bindings/blender_init.py

@@ -212,6 +212,10 @@ def sync_scene(self, renderer, depsgraph, b_scene):
 			facebuf = (c_ray.cr_face * len(faces))(*faces)
 			cr_mesh.bind_faces(bytearray(facebuf), len(faces))
 			cr_mesh.bind_vertex_buf(cr_vertex_buf(cr_scene, me))
+
+		# Set background shader
+		bl_nodetree = bpy.data.worlds[0].node_tree
+		cr_scene.set_background(convert_background(bl_nodetree))
 		return cr_scene
 
 	def render(self, depsgraph):

bindings/c_ray.py

@@ -304,7 +304,14 @@ def material_set_new(self):
 	def instance_new(self, object, type):
 		return instance(self.cr_ptr, object, type)
 	def set_background(self, material):
-		return _lib.scene_set_background(self.cr_ptr, material)
+		if material is None:
+			return _lib.scene_set_background(self.cr_ptr, material)
+		self.background = material
+		ct.pythonapi.PyCapsule_New.argtypes = [ct.c_void_p, ct.c_char_p, ct.c_void_p]
+		ct.pythonapi.PyCapsule_New.restype = ct.py_object
+		name = b'cray.shader_node'
+		capsule = ct.pythonapi.PyCapsule_New(ct.byref(material.cr_struct), name, None)
+		return _lib.scene_set_background(self.cr_ptr, capsule)
 	def vertex_buf_new(self, v, vn, n, nn, t, tn):
 		return vertex_buf(self.cr_ptr, v, vn, n, nn, t, tn)
 

bindings/cray_wrap.c

@@ -518,8 +518,12 @@ static PyObject *py_cr_scene_set_background(PyObject *self, PyObject *args) {
 		return NULL;
 	}
 	struct cr_scene *s = PyCapsule_GetPointer(s_ext, "cray.cr_scene");
-	// TODO
-	bool ret = cr_scene_set_background(s, NULL);
+	if (!PyCapsule_IsValid(node_desc, "cray.shader_node")) {
+		cr_scene_set_background(s, NULL);
+		Py_RETURN_NONE;
+	}
+	struct cr_shader_node *desc = PyCapsule_GetPointer(node_desc, "cray.shader_node");
+	bool ret = cr_scene_set_background(s, desc);
 	return PyBool_FromLong(ret);
 }
 

bindings/nodes/convert.py

@@ -5,6 +5,17 @@
 from . value import *
 from . vector import *
 
+def convert_background(nt):
+	if len(nt.nodes) < 1:
+		print("No nodes found for background, bailing out")
+		return None
+	if not 'World Output' in nt.nodes:
+		print("No World Output node found in tree for background, bailing out")
+		return None
+	root = nt.nodes['World Output']
+	return parse_node(root.inputs['Surface'].links[0].from_node)
+
+
 def convert_node_tree(bl_depsgraph, mat, nt):
 	if len(nt.nodes) < 1:
 		print("No nodes found for material {}, bailing out".format(mat.name))
@@ -27,8 +38,11 @@ def parse_color(input):
 			return NodeColorConstant(cr_color(vals[0], vals[1], vals[2], vals[3]))
 		# case 'ShaderNodeTexImage':
 		# 	return warning_color
-		# case 'ShaderNodeTexChecker':
-		# 	return warning_color
+		case 'ShaderNodeTexChecker':
+			color1 = parse_color(input.inputs['Color1'])
+			color2 = parse_color(input.inputs['Color2'])
+			scale = parse_value(input.inputs['Scale'])
+			return NodeColorCheckerboard(color1, color2, scale)
 		# case 'ShaderNodeBlackbody':
 		# 	return warning_color
 		# case 'ShaderNodeCombineRGB':
@@ -85,6 +99,12 @@ def parse_node(input):
 		case 'ShaderNodeBsdfTranslucent':
 			color = parse_color(input.inputs['Color'])
 			return NodeShaderTranslucent(color)
+		case 'ShaderNodeBackground':
+			color = parse_color(input.inputs['Color'])
+			# Blender doesn't specify the pose here
+			pose = NodeVectorConstant(cr_vector(0.0, 0.0, 0.0))
+			strength = parse_value(input.inputs['Strength'])
+			return NodeShaderBackground(color, pose, strength)
 		case _:
 			print("Unknown shader node of type {}, maybe fix.".format(input.bl_idname))
 			return warning_shader