Preparing Your Multiplier
Import your multiplier (base texture) into Photoshop or GIMP, we will use it as a base for our bump map.
Remove all logos and stencils before you proceed, as they should appear as printed on and not raised from the surface.
Go to Image -> Adjustments -> Brightness/Contrast and push the Contrast slider about 30% to the right.
Your Multiplier now should look like this:
Lighter areas on Multiplier will appear higher or "bumped out" and darker areas will appear lower or "bumped in." Just don‘t make it over-contrasted, as your object will look worse than with no bump at all!
Generating Bump Map Image
Now click Filters -> NVIDIA Tools -> Normal Map Filter and check if all the settings match the picture shown below. Make sure that “Invert Y” box is ticked! Click OK.
Now you have the standard bump map that should look like this:
Changing the Channels
The last step is very important! If you don’t do this, your bump map will cause strange lighting on your mesh in game.
Go to the channels tab and copy-paste your channels like shown in the picture below.
- The Red channel should go to the Alpha channel.
- The Green channel should go to the Red, Green and Blue channels.
The Blue channel is not used for Sims 3 bump maps.
If all went right, you will get an image similar to the one pictured.
Save your bump map as a DDS, in DXT5 compression.