diff options
Diffstat (limited to 'io_scene_obj/export_obj.py')
| -rw-r--r-- | io_scene_obj/export_obj.py | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/io_scene_obj/export_obj.py b/io_scene_obj/export_obj.py index f3b92afd..a147a493 100644 --- a/io_scene_obj/export_obj.py +++ b/io_scene_obj/export_obj.py @@ -73,9 +73,11 @@ def write_mtl(scene, filepath, path_mode, copy_set, mtl_dict): use_mirror = mat_wrap.metallic != 0.0 use_transparency = mat_wrap.transmission != 0.0 - # Convert from principled roughness to 0 - 1000 specular range. - # XXX Basic linear conversion, what would be best-matching formula here? - fw('Ns %.6f\n' % ((1.0 - mat_wrap.roughness) * 1000)) + # XXX Totally empirical conversion, trying to adapt it + # (from 1.0 - 0.0 Principled BSDF range to 0.0 - 900.0 OBJ specular exponent range)... + spec = (1.0 - mat_wrap.roughness) * 30 + spec *= spec + fw('Ns %.6f\n' % spec) # Ambient if use_mirror: |