Quote - It really takes much more than just manipulating a texture map.  Bump maps should really beseparate grayscale images with added fine details to enhance the texture maps.  Simple conversions will not provide the necessary effects.  That is why you see noise nodes added to texture maps in the Material Room to bring out some details.

Also, displacement must be activated in the render settings, otherwise you will see no bumps or displacements in your final image.

I could be wrong but I don't think you need displacement turned on for bump maps to work.

 

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