By default (on my mac anyway) it selects OpenGL,a few times i have had Carrara crash when coming back to the assembly room after changing a few shaders, i have reported this but daz hasn't done anything.

What i am wondering is what is the best one to use - OpenGL or software, and would changing it solve the problem i am having. I don't seem to have the shader to assembly room issue on windows.

Mac is up to date with patches and such