OBJ/MTL: import fails for .mtl files with texture options -o u v, -s u v #89421

New Issue

Scurest · 2021-06-25T03:26:17+02:00

Scurest commented

2021-06-25 03:26:17 +02:00

System Information
Operating system: Linux
Graphics card: Intel HD

Blender Version
Broken: 2.93
Worked:

Short description of error

MTL files allow textures to be scaled and offset with a texture option

-o u [v [w]]         # Origin offset    (default 0 0 0)
-s u [v [w]]         # Scale            (default 1 1 1)

v and w are optional, but importing currently fails with an exception for MTL files that omit v or w.

Exact steps for others to reproduce the error

Import this .obj file: MTLTextureOptionBug.zip

The important line is

map_Kd -o -0.5 -0.5 -s 2.0 2.0 WaterLilies.jpg

Details

The error is ultimately that the one- or two-element list is passed on to be assigned to the Mapping node's inputs

    self.node_mapping.inputs['Scale'].default_value = scale
ValueError: bpy_struct: item.attr = val: sequences of dimension 0 should contain 3 items, not 2

It can be fixed by expanding the list of offset/scale parameters to three elements around here .

For the relevant part of the MTL spec, open http://paulbourke.net/dataformats/mtl/ and Ctrl+F for "The -o option offsets".

Context

This was found at https://blender.stackexchange.com/questions/228486/import-obj-error-sequences-of-dimension-0-contain-3-items-not-2

**System Information** Operating system: Linux Graphics card: Intel HD **Blender Version** Broken: 2.93 Worked: **Short description of error** MTL files allow textures to be scaled and offset with a texture option ``` -o u [v [w]] # Origin offset (default 0 0 0) -s u [v [w]] # Scale (default 1 1 1) ``` v and w are optional, but importing currently fails with an exception for MTL files that omit v or w. **Exact steps for others to reproduce the error** Import this .obj file: [MTLTextureOptionBug.zip](https://archive.blender.org/developer/F10198386/MTLTextureOptionBug.zip) The important line is ``` map_Kd -o -0.5 -0.5 -s 2.0 2.0 WaterLilies.jpg ``` **Details** The error is ultimately that the one- or two-element list is passed on to be assigned to the Mapping node's inputs ``` self.node_mapping.inputs['Scale'].default_value = scale ValueError: bpy_struct: item.attr = val: sequences of dimension 0 should contain 3 items, not 2 ``` It can be fixed by expanding the list of offset/scale parameters to three elements around [here ](https://github.com/sobotka/blender-addons/blob/f86f25e62217264495d05f116ccb09d575fe9841/io_scene_obj/import_obj.py#L172-L175). For the relevant part of the MTL spec, open http://paulbourke.net/dataformats/mtl/ and Ctrl+F for "The -o option offsets". **Context** This was found at https://blender.stackexchange.com/questions/228486/import-obj-error-sequences-of-dimension-0-contain-3-items-not-2

Scurest commented

2021-06-25 03:26:17 +02:00

Added subscriber: @scurest