View Full Version : Max, Inverted normal map creation

12 December 2006, 01:57 PM
I have been experimenting with creating normal maps, by using the render to texture function in max 9, but the maps appear to be inverted. Any ideas which setting i need to change to stop this?


12 December 2006, 02:56 PM
cant see in what way they would be inverted. but most likely reason for inverted normalmaps would probably be that the uvmap is inverted too. In maya you also hade to choose world or objectspace to calculate in, so make sure no object have funny scaling (like negative or such).


12 December 2006, 05:03 PM
It looks fine to me, try inverting the green chanel

12 December 2006, 05:41 PM
It seems fine to me. I just copy and pasted your image into photoshop and used it as a normal map and it worked fine, meaning I used an omni light to test out the shadows and it's fine. How are you setting it up to display the normal map, and what are you saving the normal map as, what type of file. Can you show us your results???

12 December 2006, 05:49 PM
Thanks for all your help guys,

I was looking at this tutorial

and i saw that the normal maps there look exactly the same.

The problem i has is that until thursday comes and my new graphics card is delivered i cant see the results of the map in the viewport. I was just looking at the map and deciding that it looked inverted (which it does) and i thought this would translate through to max as being in when it should have been out.

So i have to apologise and thanks you for your assistance. I was just being a bit of dunce

01 January 2007, 04:21 PM
I could be wrong but Max flips/inverts the green channel when baking. You can always invert that channel in Photoshop afterwards.

The green should be at the top and not at the bottom of that beveled shape.

Depending on the shader you are using you can sometimes flip the channels. Max's standard normal map material allows you to do this.


01 January 2007, 05:03 PM
there is an option to flip the green channel (when projecting the normalmap) in render to texture popup. That's the easiest way to flip it.

What is weird is that if you invert the normal map green channel it displays the normal nicely in realtime but if you take beautyrenders or something it looks awfull and you have to flip green channel again. Somehow the normal dumb doens't work the same way as DX9 shaders.

01 January 2007, 09:53 PM
Thanks for the additional suggestions, ElFuego and Mindrot

In photoshop how should i go about flipping the green channel, do you mean physically with a transform or by using the invert option.

Also do you know of any resources or could you provide any tips for working with normal maps in photoshop. Perhaps editing them, or combining them with other maps?

01 January 2007, 10:09 PM

That tutorial is a bit more in depth than a pair of dice.

By inverting the green channel, we mean that you go to the channels tab, by default, embedded in the layers panel. It should have a red, green and blue channel. Click on the green, select all and then hit CTRL-I return back to the RGB channel and see the results.

01 January 2007, 10:33 PM
When you look at the actual normal map things that pop out like like they're popping in. Once its on the model though, it will look fine.

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