Texturing tutorial

This document is broken up into 8 sections outlining the different aspects of texturing and use in maps for q3 Urban Terror.

> Proper tiling
> The high pass filter
> Trim technique
> Advanced tiling
> Dirtying textures
> Misc. tips/tricks
> Map color theory
> Simple shaders (shiny windows)

The high pass filter:

The high pass filter is one of the best ways to remove tiling due to light/dark variations in the image. This is commonly referred to as "value" - for you non-artists. Many times I run the high pass filter before I go to the trouble of removing the tiling from the previous method.

In this tutorial, copy a selection of the image you wish to work with, and paste it into a new document along side the original.

Next, use the offset filter from the previous tutorial to get the image to the stage on the right again.
Tiled texture, note the value differences in the four sections
From this point, go to filter>other>high pass.
The location of the high pass filter
Now the high pass filter window should be visable. The texture is grey now, but don't worry about that right now. What you need to look for is the Radius of the high pass filter. The slider bar at the bottom needs to be adjusted so that the value of the texture stays constant throughout the entire image
The high pass filter screen
Here you can see that I have lowered the radius to 10 pixels to achieve a more balanced value across the entire texture.
Adjusting the high pass filter to an effective level
After hitting "OK", you are going to want to bring back the color of the image. To do this, go to edit>fade high pass. From here, make sure the Mode is set to Luminosity and Opacity at 100%. Hit ok and your image should return to approximately the color it started out as. I say approximately, because it varies in images for an as of yet unknown reason to me.
Fading the high pass filter on the luminosity only mode

If the image is off, you have to manually adjust it back. For this I like to have the original image next to the new image so that I can see exactly what I have to change.

As you can see, the image has darkened somewhat - the original image is on the left. So I will adjust the levels in the next image to compensate.
After the fade, the image is darker and more saturated

By going to image>adjust>levels we can see the value scale for the image. The left edge of the scale represents black, with white on the right edge. The middle constitutes grey values. To lighten an image, we move the white side towards the middle of the image until the value is what we want.

You may notice that by doing this it appears to add more color to the image, and the image gains a little saturation, so the next step will take care of that.
Adjusting the levels to lighten the image

Here we have gone to image>adjust>hue/saturation and reduced the saturation by -15 in order to match the image up more with our original.

From this step onward, you can start to remove the tiling like in the first tutorial - with the clone stamp tool. Don't forget to offset the image back to its original position.

(Not necessary just a good habit if you end up using the trim technique I describe later)
Desaturating the image to match.
And here we have the final image. I adjusted the hue a little bit to remove some of the red, but essentially there you have it.
Final texture
Next tutorial - Trim technique