Realtime Rendering

Ignis is not a rasterization based renderer like the ones used in most modern games. Therefore, it only uses the term frame very loosely. A frame consists of the user set spp (Samples Per Pixel) which is grouped by an iteration given the spi (Samples per Iteration). Depending on the actual spi (the user parameter is only considered an hint) the spp might be increased to make it a multiple of the spi.

Using igview without an explicitly set spp (via --spp) makes the rendering progressive, therefore only a single frame will be rendered.

The realtime mode in igview emulates the frame rendering and can be modified to render in different ways. All options below expect a spp to show some results.

Using the --spp-mode argument allows to set behavior when the target spp is reached. Available options are:

• fixed The rendering will finish when the target spp is reached. Ultimately only rendering a single frame. This is the default.

• capped The rendering will stop when the target spp is reached. The application will not close. Movement or other state changes will trigger a new rendering, however, still only a single frame will be rendered as the frame counter is not increased.

• continuous The rendering will restart when the target spp is reached. The frame counter will be increased each restart. Movement or change of the rendering state will still increase the frame counter and restart the rendering preemptively.

Using the --realtime command line argument will set spi=1, spp=1 and spp-mode=continuous.