Arnold Rendering in Maya: Tips and Tricks

Arnold is a hugely useful render engine, and in Maya it's been implemented as one of the main ones. In this breakdown. We'll talk about some ticks you can use while rendering in Arnold, and also how to diagnose for errors and aliasing. Hopefully this help you render your VFX and scene more effectively.

If you would like to read more on Arnold visit the Arnold render guide: HERE.

Standard Rendering Tips

  • Make sure your Arnold Plugin is turned on, otherwise it will not appear in Maya.

  • The more samples the better, but the longer the render time. The actual number of samples, is the square of the input value. If the camera's AA samples equal 4, then the total samples will equal 16. Some solid base-lines for samples to use are: AA = 7-11, Diffuse = 2, Glossy = 2, Refraction = 2, SSS =2.

  • Using Ray Depth for interior rooms and areas is recommended. However, this will also lead to longer render times. Diffuse ray depth will increment the light rays bouncing around in the scene. Refraction ray depth is the number of times a ray will be refracted. This ray depth works well with glass objects.

  • Arnold gives you the option of using TX texture files. This is a compressed file format that Arnold uses, so your textures will load faster.

  • AOVs(Arbitrary Output Variables), let you render out any shading network into images. This will allow you to have more control over your composition.

  • In the render view you can use the masking tools to filter out layers of your render. By doing this, you can diagnose renders. 

  • Area lights can be used to improve lighting, but also extend render times. By increasing the samples on the area light, you can create realistic renders more easily.

  • aistandard materials work great when you wish to create your own custom materials. There are also some material presets in ai that you can use for objects.

  • aiShaders are open source shaders built for Arnold. You can find some at anderslanglands.com. These come with custom AOVs and IDSs, more easier control over sub surface scattering, and more material presets.

  • If you are exporting your images as bump, normals, EXRs, or HDRs, you'll need to change the color-space to RAW.You can change the overall color-space of your files under the preferences and color management tabs.

Rendering Reflective Objects and Particles

  • Go to render stats, select your object, and turn on ​visible in reflections, visible in refractions, and cast shadows. Without these settings turned on, you will unable to see anything reflective/refractive.

  • You have to use ray tracing with reflections and refractions. You can also you ray tracing to create shadows, or just turn on depth shadows.

  • If you would like your particles ton drift out of a light source, or appear to fade out of one, turn on some render types. Use either Streak, Multi-Streak, point, and/or Multi-point.

  • To maximize particle illumination set the normal direction to a new value. Set it to 1 if the particles are moving towards your light sources. Set it to 2 if the particles are passing in-front of the lights, or do not move. Set the normal direction to 3 if all the particles are moving away from the light.

  • Make sure the lights are pointed at the particles, and the renderer has selected: use all lights.

 Reducing Noise in Interior Scenes

  • Use a sky background and Quad/portal lights instead of a sky-dome light. By placing the quad/portal lights where the windows or doors are, you can simulate the sun coming through the windows. If you were to have a sky dome light in the scene, the light would not completely reach into the interior scene rendering it useless. It can also create noisy shadows in the render.

  • Shining a distant light through the windows can simulate sun beams. However, make sure beam of light is smaller than the window. For unrealistic beams of light use a spot light.

  • Don't place lights too close to the windows. This will create noise around the window frames.

  • If the scene is too dark, adjust the intensity of the lights, the bounces, or the camera exposure.

  • Make sure the materials in the scene are physically based. 

  • Increase the diffuse and glossy bounces in the scene to get a more realistic render.