arnold for maya passes composite sample script

It is good practice to use this value sparingly. Increasing the diffuse samples to 3 gives an improved result. However, it produces a noisy result, especially in the corners of the scene. Increasing the diffuse samples to 1 allows diffuse rays to bounce around the scene. With diffuse samples set to 0, no light can bounce off of the surfaces, and therefore there is no indirect light in the scene. In the example below a directional light is pointing into an enclosed space. If the image darkens with the indirect diffuse gone, but the noise is still present, indirect diffuse rays are not responsible for the noise. If this ray type is responsible, then the noise will disappear. You can check if an area of noise is created by indirect diffuse noise by turning diffuse samples to zero this will effectively turn off indirect diffuse. If you've rendered AOV's you can check the indirect diffuse AOV if noise is present in this AOV only, you can be quite certain this ray type is responsible. There are a couple of different methods to determine indirect diffuse noise. It manifests as granularity in the scene, usually in shadowed areas. This is one of the most common causes of noise and can have a number of different sources. In this example, the performance hit from 1 to 6 samples was over 320%. Because indirect diffuse rays are so prevalent, this can get expensive. This shows the performance impact when increasing the number of diffuse samples ( GI_diffuse_samples). Camera (AA) Supersampling control over the number of rays per pixel that will be traced from the camera.

Increasing the number of diffuse samples will increase the number of diffuse rays fired from a point:ĭiffuse samples ( GI_diffuse_samples): 1 2 4 6. Noise is introduced when there are insufficient rays to resolve the range of values from the environment. The rays are fired in random directions within a hemispherical spread. When diffuse samples are more than zero, camera rays intersecting with diffuse surfaces fire indirect diffuse rays. The exact number of hemispherical rays is the square of this value. Increase this number to reduce the indirect diffuse noise. Remember that the diffuse sampling is done for each Camera (AA) sample, so high values for both Camera (AA) samples and diffuse samples will tend to result in slow renders. Therefore when you increase the Camera (AA) samples to get better geometric anti-aliasing, you should decrease the others to compensate.Ĭontrols the number of rays fired when computing the reflected indirect-radiance integrated over the hemisphere. For example, 6 Camera (AA) samples and 6 specular samples = 6 2 x 6 2 = 1296 rays per pixel for the diffuse, and another 1296 rays per pixel for the indirect specular. Camera (AA) samples multiply diffuse, specular, and light samples after being squared.

Arnold for maya passes composite sample script