Lighting Tab

The parameters on the Lighting tab in Filter Controls define the lighting conditions for the surface rendered by a filter. For lighting, Filter Forge uses spherical high dynamic range images (HDRI) shot on real-world locations, which allows to 'transfer' real-world lighting to surfaces generated by Filter Forge. Lighting is available for Surface filters only, Simple filters do not have the Lighting tab (for details, see the Filter Types section of the Result topic). The tab has the following parameters:

Orientation controls the rotation of the HDRI sphere around the surface generated by a filter (the surface always 'stands' in the center). To adjust the orientation, rotate the sphere by clicking and dragging it rightwards or leftwards.

Environments are spherical high dynamic range images reproducing real-world lighting. Filter Forge comes with a set of HDRIs shot on various real-world locations and supplied courtesy of Sachform Technology. You can also import your own HDRIs using the HDRI Import dialog.

Brightness adjusts the amount of light that reaches the surface from the HDRI sphere. The values range from 0 to 500. The default value is 100, which means that 100% of light from the sphere gets to the surface. With Brightness set to 0, no light reaches the surface, and therefore the resulting image is completely black. When Brightness is 500, the surface receives five times more light than there used to be in the original real-world scene.

Saturation controls the amount of color in the incoming light. The Saturation value ranges from 0 to 100, where 0 completely eliminates color from the lighting, and 100 preserves the original lighting color. It is recommended to leave the Saturation at 100, unless you want to achieve some special look or use a synthetic HDRI environment.

Surface Height adjusts the height of the surface which is being lit. Internally, Filter Forge represents Surface filters as pseudo-3D surfaces with each point having a different height. You don't see this height directly because you are looking at the surface 'from above' – but you can see how the light coming from the HDRI environment interacts with the surface. The Surface Height slider lets you scale this height and see how it affects the lighting: the value of 0 produces a completely flat surface which will be lit uniformly, and the value of 100 results in a surface having the maximum height.

Surface Height and Real-World Surfaces

If your goal is just to make a good-looking picture for web or for print and you aren't planning to use normal maps, you can adjust the Surface Height slider freely, without any specific considerations – just choose a value that produces the best-looking result. However, if you are imitating a real-world surface or planning to use the resulting texture in a 3D package or a game engine that makes use of normal, bump or displacement maps, you should choose the Surface Height value corresponding to the usual height of the surface you want to imitate. For information about choosing a realistic Surface Height value, see the Height section of Result.