I have been working on an iOS QCAR app that runs on an iPad. The app uses frame markers and the augmentations are 3 different models of some fish. The fish look great, they use Transparent/Cutout/Bumped Specular shaders in Unity. But occasionally the fish will go dark, or even black and just seem to be silhouettes. Could this be due to the shaders being used? Unity warns that they are expensive for the iOS platform. Has anyone else had this issue and have any suggestions? Thanks!