Selectively ignore parts of the scene

In certain scenario's, you might find yourself with an object or shader that causes Lentil to slow down significantly - without much perceptible change. This can happen for example with large bright diffuse surfaces, where a lot of the visible area might be above your selected Param: minimum_luminance_threshold.

You can create a custom AOV called lentil_ignore of type FLOAT to selectively ignore parts of the render using default arnold workflows (usually using the aov_write_* shaders). What you feed into this AOV is up to you. As soon as there is the value is larger than zero (> 0.0) for the specific subsample, it will be ignored.

The following example is a little bit contrived, but shows the way it works quite well.