In this lesson, you used the mental ray for Maya renderer to check the image quality of two frames before you started to batch render. When you create scenes with sophisticated animation, it’s useful to batch render with low-quality resolution to check the animation accuracy before batch rendering with production-quality resolution. For instance, you might preview your animation with the frames resulting from batch rendering at a small image size (320 by 240) with Preview as your Quality Preset.
Hardware rendering leverages the power provided by hardware graphics cards to render your images. The benefits of hardware rendering include the ability to batch render frames more quickly than with software rendering, and rendering specific particle effects not possible through software rendering. For more information about hardware rendering particles, see . In some cases, the image quality may be good enough for final use. You access the hardware renderer by selecting .
It's often useful to render attributes of your scene in different passes and combine them using compositing software. For example, you can render each of diffuse, shadow, reflection, specular, and ambient occlusion in a separate pass and then composite the passes afterwards. You can select a subset of the objects or lights in your scene to contribute to each render pass. You can render an unlimited number of render passes, and then group them into logical groups called render pass sets. For more information about render passes, see in the Maya Help.