Research & Development for 3D & the Web

A quick, rough reference guide relating to Bump Mapping.

Save your ‘colour’ PSD file from photoshop as the ‘master’ file.

Save another copy to be the ‘bump’ file which we can plug into the texture in Maya as the Bump Map file.

CTRL-SHIFT-U makes things black and white (it’s the shortcut for ‘desaturated’

Do this for any layers which we DO want to be bumped.

All other layers can just be binned as we don’t want them to be affected.

Anything that is WHITE is what will be affected by the bump (similar to alpha channels etc where 1 is considered on and 0 is considered off (black)).

CTRL-I is the shortcut for ‘inverting’ the colours. so it can be used for making our now black coloured/desaturated sections to white, which means they will then be affected by the bumping and the white parts of the layer become black meaning they don’t get affected.

One neat trick is to use ‘Levels’. The shortcut for Levels is ‘CTRL-L’. anything to the right is the white and anything to the left is the black levels. Adjusting these makes the whites ‘whiter’ and the blacks ‘blacker’ etc.

Once happy with the initial pass, save it out as a .tga or whatever and plug it into the texture in Maya. You can then render it out and see how it looks and use the bump-tab in the Attribute Editor to adjust the Bump Depth Slider value and therefore how heavily the bump should affect the model.

If you run into a situation where sections of the model are pushed out and some are pushed in with the bumping effect, we can simply invert one group of these so that they all go in or come out the same.

To do this, marquee shift-select the areas you wish to change and go to Layer > New Adjustment Layer > Invert. This will invert the sections you selected and therefore invert the direction of the bump for those sections as well when you update the texture in Maya.

Obviously if the whole model’s bump effect is inwards and you want it outwards (or visa versa) you can just make the value of the Bump Depth Slider the negative value of what it is set to to invert the bumping effect.