FBX: add support for more FBX freamrate modes, since stupid Unity does not hanle 'Custom' one.

Should fix Unity timeline weirdness (as long as you use standard framerates like 25fps, 30fps, 29.97fps, etc.).

io_scene_fbx/export_fbx_bin.py

@@ -134,6 +134,10 @@ def matrix_to_array(mat):
     return tuple(f for v in mat.transposed() for f in v)
 
 
+def similar_values(v1, v2, e=1e-6):
+    """Return True if v1 and v2 are nearly the same."""
+    return abs(v1 - v2) * max(abs(v1), abs(v2)) <= e
+
 RIGHT_HAND_AXES = {
     # Up, Front -> FBX values (tuples of (axis, sign), Up, Front, Coord).
     # Note: Since we always stay in right-handed system, third coord sign is always positive!
@@ -164,6 +168,24 @@ RIGHT_HAND_AXES = {
 }
 
 
+FBX_FRAMERATES = (
+    (-1.0, 14),  # Custom framerate.
+    (120.0, 1),
+    (100.0, 2),
+    (60.0, 3),
+    (50.0, 4),
+    (48.0, 5),
+    (30.0, 6),  # BW NTSC.
+    (30.0 / 1.001, 9),  # Color NTSC.
+    (25.0, 10),
+    (24.0, 11),
+    (24.0 / 1.001, 13),
+    (96.0, 15),
+    (72.0, 16),
+    (60.0 / 1.001, 17),
+)
+
+
 ##### UIDs code. #####
 
 # ID class (mere int).
@@ -2703,14 +2725,15 @@ def fbx_header_elements(root, scene_data, time=None):
     # Global timing data.
     r = scene_data.scene.render
     fps = r.fps / r.fps_base
-    f_start = scene_data.scene.frame_start
-    f_end = scene_data.scene.frame_end
-    elem_props_set(props, "p_enum", b"TimeMode", 14)  # FPS, 14 = custom...
-    #elem_props_set(props, "p_timestamp", b"TimeSpanStart", int(units_convert(f_start / fps, "second", "ktime")))
-    #elem_props_set(props, "p_timestamp", b"TimeSpanStop", int(units_convert(f_end / fps, "second", "ktime")))
+    fbx_fps, fbx_fps_mode = FBX_FRAMERATES[0]  # Custom framerate.
+    for ref_fps, fps_mode in FBX_FRAMERATES:
+        if similar_values(fps, ref_fps):
+            fbx_fps = ref_fps
+            fbx_fps_mode = fps_mode
+    elem_props_set(props, "p_enum", b"TimeMode", fbx_fps_mode)
     elem_props_set(props, "p_timestamp", b"TimeSpanStart", 0)
     elem_props_set(props, "p_timestamp", b"TimeSpanStop", FBX_KTIME)
-    elem_props_set(props, "p_double", b"CustomFrameRate", fps)
+    elem_props_set(props, "p_double", b"CustomFrameRate", fbx_fps)
 
     ##### End of GlobalSettings element.