Ambient lighting/colour issues with vtkOBJImporter
I've been working using the OBJImporter example (but without textures, just the .mtl file) and I'm finding that consistently the ambient light/colour is "blown out" (too bright). I've attached a very simple code example to describe the issue.
If I change the ambient coefficient manually on each actor down to 0 the models look fine, but if let the importer set the coefficient it does a terrible job. In the example provided it completely whites out the models, but in other tests it just generally appears far far too bright (I'm not really in a position to share the other models publicly I'm afraid).
If you toggle the commented out line 45 in my code you will be able to see the dramatic difference as shown in the examples.
I'm happy because I have a "solution" (line 45) - but something seems a bit fundamentally off?
Any suggestions on fix this? Happy to help work on a solution if needs be.
Platform wise: macOS High Sierra, using VTK 8.1.1 (complied from homebrew, with QT support)