View Full Version : ZMazpper Problem - Things Turn Out Reversed

08 August 2009, 05:34 PM

Despite the fact that I am using the 3dsmax8modifiedE.zmp custom configuration, my Normal maps seem to be "reversed" (see screenshot). I have tried other ZMapper presets and the same thing seems to be happening.

The normals from the original Max model are all in the correct orientation so I know it's not a flipped normals problem. Beyond that, I am lost.

Things like the pitting in the stone surface seem to be appearing correctly but things like the direction of the gently "bowed-out" flatter surfaces seem to be "bowing-in". I am terribly confused as to what I am doing wrong.

Can someone please help out a non-technically-minded newbie to ZBrush?

Thank you in advance.

Oh, I am using:

ZBrush 3.1

3DS Max 9

08 August 2009, 08:25 AM
If it is not the normals of the model in 3DSMax that is causing this it is most likely the normal map itself. The required orientation of the RGB channels varies from application to application. In zmapper you can flip the red and green channels separately. You will have to experiment with the right combination.

There might be some switches in 3DSMax to tell the program a normal map with a different RGB orientation is used. I don't use 3DSMax but I would guess such switches would be under the material used.

It is also possible to flip the RGB channels manually in Photoshop. Load the Normal map texture, disable the Green and Blue channel and invert the remaining Red channel. Reenable the Green and Blue channel and save. Not saying it is the Red channel that is the problem. You will have to experiment.

Hope that helps.

08 August 2009, 01:37 PM
Thanks for your reply, TVeyes!

08 August 2009, 07:27 PM
Yup I ran across this problem in Lightwave. I had to use Tangent Coordinates and it worked without it hitch.

Tools-->Normal Map-->Tangent.

08 August 2009, 11:37 PM
Thanks for your input, Jonathan! I tried your suggestion but the problem is still persisting.

I'm on the verge of becoming a Mudbox user over this.

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