Load OBJ Model BUG

Hello everyone,

I’m loading obj files in my Java application and … it works!

Therefore, the models are coming flipped in the X-axis and to fix it I’ve change my obj reader to multiply the X-axis by -1. I know that isn’t the perfect solution so I’m trying to figure out what is happening.

When I load objects in the normal way (without -1), all my textures also became flipped.

Some useful information to help me (I believe that is)

  • OBJ exported in blender, including vertices, uvs and normals. The Y axis is selected as UP and forward is -Z
  • The camera in the application is in position 0, 5, -30 and pointing to center.
  • Camera settings are fov 70, aspect 1920 / 1080, zNear 0.01f, zFar 1000.0f

Things that “solve” the problem

  • Load object with -1 x X position;
  • Scale objects to -1 in X axis
  • Change the aspect of camera to negative value
  • A lot of different things that I’ve tested, therefore it changes other things and orientations… breaks everything

Sorry for this newbie question, but I’m little curious about it.

Have you tried changing the projection matrix to work in the axis system your data comes from? (Y up)