Opengl Mirror transform backface culling
culling, opengl
Solution
You can simply switch the culling mode. You can use `glCullFace(mode)` to decide which triangles should be culled. Supplying a parameter of `GL_BACK` means that only front-facing polygons are rendered, while a parameter of GL_FRONT means that only backfacing polygons are rendered. So if your transformation means that the "backfacing" polygons are in fact frontfacing, calling `glCullFace(GL_FRONT)` should do the trick.
As an alternative you can also control which polygons are considered front/backfacing using `glFrontFace(dir)`, with a parameter of `GL_CW` (clockwise) or `GL_CCW` (counterclockwise) (default is counterclockwise so if you set it to clocksie originaly backfacing polygons would be considered frontfacing).
Problem
In openGL, I've got an object that I scale by -1 along an axis... this results in the object not rendering properly because all the front faces are now back faces. Short of disabling culling, how would I get this object to render right? Is there a way to do it without modifying the textured normal vertices that make up my model?