What I'm trying to do is take a photo, pick a pixel location in the photo to place a hologram, then actually place the hologram in the corresponding 3D location. I found a tutorial for this here under "Pixel to Application-specified Coordinate System": https://developer.microsoft.com/en-us/windows/holographic/locatable_camera. However, the code for the translation between the pixel coordinate to real world coordinate is in shader code. I created a custom shader and a material for that shader, but my question is how does the shader code snippet provided in that link actually fit into the shader file? Also, to what gameobject should the material be attached? As a bonus, it'd be great if anyone could explain why this is done in shader code. This thread http://forum.unity3d.com/threads/locatable-camera-in-unity.398803/ has clues on what I want to accomplish, but the shader code is not included.