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Getting Animated Normal Maps

Hi everyone. I’m having trouble with an animated normal map. I have created a normal map video as a wmv file and imported that into UE4. I can use it in my material as a base colour with no problems but when I use it as a normal map it seems a little off. I have a fresnel effect in my material and when I attach the normal map the fresnel becomes lopsided, showing more on the right of the mesh than the left. Here’s how it looks, the fresnel is multiplied by a green colour and added to the emissive.

Fresnel.PNG

I have a feeling this is to do with the adjustments UE4 makes when it imports a normal map since it makes no adjustments to video files. Could someone tell me if I am correct and if so, how can I replicate these adjustments in after effects?

Thanks in advance
Noah

For a normal map in a movie texture you should bias scale the values from 0 to 1 into the -1 to 1 space.

So place ‘constant bias scale’ and set the ‘bias’ to -0.5 and the scale to 2. It applies the bias first which makes it go from -0.5 to 0.5 and then the *2 makes it from -1 to 1. When you import a texture as a normal map it does that part under the hood but there is no such option for movie textures.

Thank you so much! It looks perectly normal now :slight_smile: . However I had to use a bias of -0.25 rather than -0.5. Maybe the scale multiplies the bias first. Whatever the case it now works.