Wavefront OBJ toolbox

Read and Write Wavefront OBJ geometry and MTL files

Description

Read and Write Wavefront OBJ geometry and MTL files.

A Wavefront Geometry Object file is supported by many 3D programs, it looks like:
v 0.000000 2.000000 0.000000
v 0.000000 0.000000 0.000000
v 2.000000 0.000000 0.000000
v 2.000000 2.000000 0.000000
% Vertices Coordinates 4
f 1 2 3 4
% Faces 1

The function read_wobj allow Wavefront object files including material MTL files to be read into a Matlab structure.
The function write_wobj exports a Matlab structure to an OBJ file.

It doesn't matter if the object file contains splines or polygon based geometry, it reads and writes almost all .obj files.

See "help read_wobj" and "help write_wobj"

Comments and bug reports are welcome

• MATLAB release: MATLAB 7.10 (2010a)

[Jun wan]

it's great work! thanks

[Jun wan]

Hi,Jan:
     thanks for your code.I have a question that how can i using the texture data when show the 3D objtect? In your code ,you only used in vertices and faces. Looking forword to your answer.

[haidi]

Too slow for large models!

[Dirk-Jan Kroon]

*haidi
I know the for-loop is killing the speed in Matlab, especially because the wavefront obj. format is really broad.
If you know your data at forehand, you can remove probably more than 80% of the lines of code.

[Paul]

So far this is a good find. I have found a bug if the file name of the obj contains a space. In line 69 of read_wobj.m: filename_mtl=fullfile(filefolder,data); returns the error:

??? Undefined function or method 'eq' for input arguments of type 'cell'.

Error in ==> fullfile at 39
      elseif (f(end)==fs) || (part(1)==fs || (bIsPC && (f(end)=='/' || part(1)=='/')) )

[Jaroslaw Tuszynski]

Worked great!

[Oliver Woodford]

Works well, good help text, well written.

[Oliver Woodford]

However, it is painfully slow at reading larger files.

[mourad raafat]

Rely good work but it give me that error so any one can help me cause i'm anew user for matlab
??? Error using ==> fread
Invalid file identifier. Use fopen to generate a valid file identifier.

Error in ==> read_wobj>file2cellarray at 298
file_text=fread(fid, inf, 'uint8=>char')';

Error in ==> read_wobj>readmtl at 363
file_words=file2cellarray(filename_mtl);

Error in ==> read_wobj at 78
            material=readmtl(filename_mtl,verbose);
and that in read file
thanks for help

[mclaudt]

mourad, check filename for correct slash orientation.

Under Linux, you should use
OBJ=read_wobj('examples/example10.obj')
instead of
OBJ=read_wobj('examples\example10.obj')
from commented example.

[Dalia Nabil]

I tried this on an obj file created by meshlab and it returned this error

 
% OBJ File Generated by Meshlab
  %
  % Object example-cloud.obj
  %
  % Vertices: 197749
  % Faces: 0
  %
??? Subscripted assignment dimension mismatch.

Error in ==> read_wobj at 90
                vertices(nv,1:4)=data;

do you know how to fix it ? or how to obtain a 3d coordinates from meshlab?
thanks

[amroun]

I tried this on an obj file created by meshlab and it returned this error

  
% OBJ File Generated by Meshlab
  %
  % Object example-cloud.obj
  %
  % Vertices: 197749
  % Faces: 0
  %
??? Subscripted assignment dimension mismatch.

Error in ==> read_wobj at 90
                vertices(nv,1:4)=data;

do you know how to fix it ? or how to obtain a 3d coordinates from meshlab?
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

I have the same problem as Nabil. you have found the solution? Thank you

[Joe Wang]

Works well for me but question is how to show the mesh model in Matlab?