Normal values ?

Hello Everyone,

i got really confused today about my knowledge of Normal maps and the effect of their Values.
I just get to the point, why a Vector3 plugged into the Normal Slot with the values of “0.5 0.5 1.0” is changing my normal and one with the values of “0 0 1.0” is not ?

As far as my knowledge goes the value of 0.5 0.5 1.0 (or 128 128 255) is the flat or Up value for a normal map.

I would really appreciate to get an answer to this probably stupid question.



In UE4 use 0,0,1 for flat normal.

Edit: I’m not really sure why.

In cryengine 128,128,255 is flat normal. But in Cryengine Z is up. In UE4 Y is up. I’m guessing 0.5,0.5,1 in UE4 doesn’t correspond to the correct direction. Stupid ideas of mine.

In UE4, 0,0,1 is a resting point directly above the top normal. Going in the negative direction on the x/r value, -0.3, 0, 1, would shift the normal to the left. The positive direction, 0.3, 0, 1 shifts it to the right.

The texture normals blended with the vertex normals result in the final normals used for the object. In your textures, 128,128,255, or 0.5,0.5,1 is converted to a range of -1:1 so that 128 = the halfway point, or 0.

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