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Incremental mode is the other alternative. Here, the renderer goes round-robin and visits every pixel in the image, computing a single sample for each. Then it visits each pixel again and computes a second sample, etc. This goes until it has visited each pixel a sufficient number of times. When displayed to a framebuffer the entire image appears swiftly in a rough and noisy form which then refines bit by bit over time. This allows one to get a quick sense of how the final image will look and to cancel it if it becomes clear that adjustments are needed. However, the total render time may be longer. Also, some renderer settings (e.g., PxrVCM and PxrUPBPPxrUnified) may require this mode.

Please note that frames with many AOVs and large resolution may require significantly more memory in incremental mode because RenderMan must keep the entire framebuffer in memory.

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