The Rendering tab of the Options dialog lets you adjust the parameters affecting the Filter Forge renderer. The Options dialog is accessible by choosing Tools > Options from the Main Window menu.
Switches the renderer between using a single CPU/core or all available CPUs/cores. This option applies only to computers with two or more CPUs or cores, it has no effect on single-CPU/single-core systems. On a multi-core system, you might want to use a single CPU/core to save processing power for other tasks, or to measure the performance boost provided by a multi-core system over a single-core system. The Basic and Standard editions of Filter Forge are limited to dual-core CPUs, while the Professional edition supports quad-core and higher processors. See Filter Forge Editions for more information.
Defines how the normal maps are generated. Filter Forge can generate both DirectX-style and OpenGL-style normal maps. The default setting is DirectX-style, where the Y values (green channel) are positive – the map looks like a blue relief is 'lit' with a green light from below. In OpenGL-style normal maps, the Y axis is flipped so the green 'light' appears to come from above. The red and blue channels in both types of maps are identical. Normal maps are only available in the Professional edition of Filter Forge. See Filter Forge Editions for more information.
When turned on, the renderer applies dithering to the output image. Dithering is a method of simulating shades that are absent in the color palette by mixing pixels of the nearest colors available in the palette. Dithering helps reduce unwanted artifacts known as color banding that occur in color gradients during the conversion from the internal Filter Forge color depth (double-precision floating point) to the target color depth (usually 8 or 16 bit per channel). Filter Forge uses noise-based dithering (as opposed to pattern-based dithering).
When turned on, the preview image is rendered in two passes: the first pass produces a non-anti-aliased image, and the second pass applies anti-aliasing. When this option is turned off, the preview is rendered in a single pass which produces the final anti-aliased image. With progressive previews turned on, you see the rendered result sooner but in lower quality. When this option is turned off, you see the preview in final quality but it takes longer to render.
When turned on, causes all blur-based components (such as Blur, High Pass or Sharpen) to use an integer blur radius instead of a floating-point radius in cases when the internal blur radius exceeds 40 pixels. This optimization allows to avoid sub-pixel calculations for cases where their contribution to the final result is negligible. When this option is turned off, the blurs are more accurate, but the quality improvement is usually marginal.
When turned on, randomizes sample positions within a pixel being anti-aliased, which helps eliminate unwanted artifacts that occur in high-frequency pattern textures during anti-aliasing. Jittered sampling affects anti-aliased pixels only and has no effect when anti-aliasing is turned off. When this option is set to Off, samples within a pixel are always taken at the same positions on a regular grid. When set to any other value, a random offset is applied to the sample positions – the higher the value, the more chaos is introduced. For more information, see Anti-Aliasing Menu.
Allows to select the location for temporary files which Filter Forge may create during the rendering. The default location is the system %Temp% folder; however, if you are low on disk space on the disk where the %Temp% folder is located, you can select another location. It's recommended to have at least 1 GB of free space on the selected disk.
Sets the maximum percentage of physical memory available to Filter Forge. The default value is 60%, the minimum is 10%, and the maximum is 90% – Filter Forge never uses up all available memory. Regardless of the slider value, Filter Forge will never consume less than 128 MB and more than 1500 MB of memory.
When turned on, all bitmap-based components will operate on anti-aliased sources. Turning this option on increases the output quality, especially for small-radius blurs with high-frequency sources, but can significantly increase the rendering time. It is recommended to turn this option off, unless strictly necessary.
When turned on, the preview size for large images is automatically reduced. Technically, this option simply activates the View > Preview Size > Reduced menu command for images that don't fit into the preview pane without being zoomed out.
When turned on, a notification showing the elapsed rendering time is displayed in the preview pane of the Main Window after the rendering is complete. This option can be used for comparing different versions of a filter to figure out which one renders faster.