io_scene_fbx/__init__.py

@@ -482,6 +482,13 @@ class ExportFBX(bpy.types.Operator, ExportHelper):
             description="Export vertex color attributes",
             default='SRGB',
             )
+    prioritize_active_color: BoolProperty(
+            name="Prioritize Active Color",
+            description="Make sure active color will be exported first. Could be important "
+                        "since some other software can discard other color attributes besides the first one "
+                        "(e.g. 3ds Max, Substance Painter)",
+            default=False,
+            )
     use_subsurf: BoolProperty(
             name="Export Subdivision Surface",
             description="Export the last Catmull-Rom subdivision modifier as FBX subdivision "
@@ -787,6 +794,7 @@ class FBX_PT_export_geometry(bpy.types.Panel):
         #~ sub.enabled = operator.mesh_smooth_type in {'OFF'}
         sub.prop(operator, "use_tspace")
         layout.prop(operator, "colors_type")
+        layout.prop(operator, "prioritize_active_color")
 
 
 class FBX_PT_export_armature(bpy.types.Panel):

io_scene_fbx/export_fbx_bin.py

@@ -1257,7 +1257,12 @@ def fbx_data_mesh_elements(root, me_obj, scene_data, done_meshes):
         fbx_lcidx_dtype = np.int32
         t_lvi = None
 
-        for colindex, collayer in enumerate(me.color_attributes):
+        color_attributes = me.color_attributes
+        if scene_data.settings.prioritize_active_color:
+            active_color = me.color_attributes.active_color
+            color_attributes = sorted(color_attributes, key=lambda x: x == active_color, reverse=True)            
+
+        for colindex, collayer in enumerate(color_attributes):
             is_point = collayer.domain == "POINT"
             vcollen = len(me.vertices if is_point else me.loops)
             # Each rgba component is flattened in the array
@@ -3290,6 +3295,7 @@ def save_single(operator, scene, depsgraph, filepath="",
                 bake_space_transform=False,
                 armature_nodetype='NULL',
                 colors_type='SRGB',
+                prioritize_active_color=False,
                 **kwargs
                 ):
 
@@ -3357,7 +3363,7 @@ def save_single(operator, scene, depsgraph, filepath="",
         add_leaf_bones, bone_correction_matrix, bone_correction_matrix_inv,
         bake_anim, bake_anim_use_all_bones, bake_anim_use_nla_strips, bake_anim_use_all_actions,
         bake_anim_step, bake_anim_simplify_factor, bake_anim_force_startend_keying,
-        False, media_settings, use_custom_props, colors_type,
+        False, media_settings, use_custom_props, colors_type, prioritize_active_color
     )
 
     import bpy_extras.io_utils

io_scene_fbx/fbx_utils.py

@@ -1489,7 +1489,7 @@ FBXExportSettings = namedtuple("FBXExportSettings", (
     "bone_correction_matrix", "bone_correction_matrix_inv",
     "bake_anim", "bake_anim_use_all_bones", "bake_anim_use_nla_strips", "bake_anim_use_all_actions",
     "bake_anim_step", "bake_anim_simplify_factor", "bake_anim_force_startend_keying",
-    "use_metadata", "media_settings", "use_custom_props", "colors_type",
+    "use_metadata", "media_settings", "use_custom_props", "colors_type", "prioritize_active_color"
 ))
 
 # Helper container gathering some data we need multiple times: