The Adaptive AMC engine is based on the Unbiased TR2 engine but with shortcuts to make it faster. It should be preferred for difficult, indirect lighting situations (e.g., indirect caustics) and it can be used in both Interactive and Production Mode.
Tracing Depth: Just like in the Presto Engine, this is an important parameter for Progressive Engines. Increasing this parameter may be needed for certain cases where there are a lot of mirrors or dielectrics in the scene, but there is no direct impact on render times.
Adaptive Bias: By increasing this value, several difficult paths are taken out of computations, making it faster.
Caustics: Enabled or disabled the caustics path. In general, it should always be enabled.
When rendering interactively, screen resolution is used instead of camera resolution. Disable the ‘Interactive’ option to render at full size.