Original Post
Hi.
Im creating a heightmap from a 16 bit channel in a texture that came from a 16 bit per channel png image using the vertex shader. I was thinking that instead of using a seperate texture for the normal map I might as well put both the normal and height map in a single 16 bit per channel (64 bbp) png image. RGB would become the normal map and Alpha would be the height map. This would also greatly simplify the process of creating height and normal maps in photoshop using the nifty normal map plugin from nvidia. Using this way I also bind one less texture but I dont know how much of an advantage that is. I dont know if the end result will have any noticeble quality improvement.
Is this aproach fine or should i rather save the normal map in a seperate 8 bits per channel image.
Im creating a heightmap from a 16 bit channel in a texture that came from a 16 bit per channel png image using the vertex shader. I was thinking that instead of using a seperate texture for the normal map I might as well put both the normal and height map in a single 16 bit per channel (64 bbp) png image. RGB would become the normal map and Alpha would be the height map. This would also greatly simplify the process of creating height and normal maps in photoshop using the nifty normal map plugin from nvidia. Using this way I also bind one less texture but I dont know how much of an advantage that is. I dont know if the end result will have any noticeble quality improvement.
Is this aproach fine or should i rather save the normal map in a seperate 8 bits per channel image.
They show that the quality result is very good, but there's quite a few ALU ops required in the decoding. However, seeing as your vertex shader is performing texture fetches, then you're going to get a certain amount of ALU ops "for free" anyway to cover that fetch latency.
