Error details: Some materials definitions were not found, a default white material is used where no material was available.
Anyone dealing with 3D models through photogrammetry or modelling programs who use the wonderful Meshlab or Cloud Compare programs may have come across the above error.
The cause of this is down to the programs not being fully happy with spaces in file names and their material definition files – the .mtl file.
To fix the issue remove all spaces from files names, edit the .mtl file and .obj files in a text editor accordingly.
When you remove the spaces inside the .mtl and .obj files be sure to remove any quote marks “”.
edit Object file in text editor
mtllib “my file.mtl” usemtl my-file
mtllib my_file.mtl usemtl my-file
edit .mtl file in text editor
… … map_Kd “my file-tex.jpg”
… … map_Kd my_file-tex.jpg
But I didn’t have any spaces…
If you haven’t used spaces in your files and you still have the problem then sometimes programs will include the quote marks “” even if you haven’t used spaces and Meshlab and CloudCompare will still fail.