6.4.3 Termination criteria attributes

Iray tab in the Render Settigns Window when Iray Photoreal is selected
Min. Samples
Controls the minimum number of iterations that need to be rendered before the progressive render loop is allowed to terminate by any of the termination criteria.
Max. Samples
Sets the maximum numbers of iterations to be calculated. When this number is reached Iray stops the calculation of the image.
Max. Time
Sets the time limit for the rendering in hours:minutes:seconds. When the render time exceed the value in this attribute Iray stops the calculation of the image.
Quality Estimate Enabled
The convergence quality estimate is only available in the non-interactive render mode and can, in addition, be enabled and disabled with this attribute. If disabled, rendering will not stop based on the convergence quality and no progress messages will be issued for the current convergence quality.
A convergence estimate for a pixel has to reach a certain threshold before a pixel is considered converged. This attribute is a relative quality factor for this thresh-hold. A higher quality setting asks for better converged pixels, which means a longer rendering time. Render times will change roughly linearly with the given value, i.e., doubling the quality roughly doubles the render time. The value range for this attribute is 0 to 100.
Converged Pixel Ratio
If the progressive rendering quality is enabled, this attribute specifies a threshold that controls the stopping criterion for progressive rendering. The value range for this attribute is 0 to 1. Higher values will increase quality but also render time.