The Elevation/Texture and Vertical Enhancement sliders are the main controls. Moving the Elevation/Texture slider to the right increases the amount of texture shading and moving it to the left increases the amount of elevation data that appear in the rendered image. Moving the Vertical Enhancement slider from left to right increases the apparent contrast in the image.
Set the width and height to match the size of shaded relief image you will be combining with the texture shade. Doing this allows you to copy and paste images from one file to another in Photoshop. TTS saves rendered images as GeoTIFFs, useful for working with a GIS.
The default TTS render settings are a good place to start for your first texture shading. I also recommend rendering several others at different settings to give you design options later when working in Photoshop. Try moving the top slider right to 100 or 150. Render again and save the image. Next, move the bottom slider left to 2 or 3. Be sure to save the renderings with new names that you can easily identify.
The real magic of texture shading happens in Photoshop.
1) Open your texture shading and the shaded relief you will combine with it. Copy and paste the shaded relief on a layer above the texture shading.
2) With the blending mode of the shaded relief layer set to the default "Normal," reduce the layer opacity allowing the texture shading below to show through. In general, setting the shaded relief layer opacity between 50 and 80 percent works well for most terrains.
3) When the shaded relief layer opacity is closer to 50 percent, it may be necessary to add supplemental relief shadows. Follow this procedure:
– Duplicate the shaded relief layer and set the opacity of the duplicated layer to 100 percent.
– Use a curves adjustment to remove all value from flat areas, such as water bodies. Do this by sliding the highlight end of the curves adjustment horizontally until flat areas appear completely white.
– Set the layer blending mode to "Multiply" and reduce the opacity considerably until the relief shadows look pleasing.
4) Other options include applying a "Curves" adjustment layer to the texture shading layer or an overall "Levels" adjustment to lighten or darken the entire image. Every terrain is different and a certain amount of experimentation is required to get the best results. Examine the linked file below to get an idea of how this is done.
Layered Photoshop file with combined shaded relief and texture shading (1.4 MB).
5) Finally, the procedure above will create a gray composite relief in RGB color mode, which can look sterile and metallic. Use a "Hue/Saturation" adjustment layer to tint the relief a more attractive color.