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This is the traditional way to use the parameter. But you may wish to use partial presence values in rendering for something semi-opaque. By default, we use a stochastic method to determine presence. This means we randomly sample at varying levels of presence when the value is not a 0 or 1. This can generate noise and require more samples to clear up or converge. Below we have a set of overlapping planes set to a Presence value of 0.15. Notice that lower presence values will show more noise than higher values.

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