Default Rendering Settings

• Shadows.  Objects cast shadows when light is directed towards them.
• Ray Tracing.  The quality of the rendering is enhanced by the repeated tracing of the path of rays from the scene’s light sources.  Ray tracing enhances reflections and refracted light on parts.
• Antialiasing.  This high-quality rendering method allows parts to be displayed with smooth and well-defined edges.  This definition is improved by interpolating pixels of intermediate colors along the part’s edges.  Choosing this option also enables true transparency and soft shadows.

Image

Size.  The size of the rendering.  The size may be a fraction of the window size—or an absolute size specified in pixels.

Fill Pattern.  The order in which blocks of pixels are rendered.  This defines the order in which areas of the rendering become visible.

• Random.  The blocks are rendered in a random pattern.
• Spiral.  The blocks are rendered in a pattern spiraling out from the center to the edges of the image.
• Scan.  The blocks are rendered from left to right and top to bottom.

Ray Depth.  The number of times a ray is allowed to hit something when ray tracing.  A limit must be placed on the number of bounces because situations may result in otherwise infinite bouncing.  Two perfectly parallel mirrors would result in rays that bounce back and forth forever.  Higher numbers may increase render times.  A value too low will result in poor reflections and refractions.

Mask-out Background.  Select this option to mask-out the background so that it is not rendered in the final output. This is helpful to mask out 3D Environments used for lighting conditions but are not useful in the rendered background.

Show SaveAs Warning. Select this option to show or hide a warning message to save the rendered result window.

Super-Sampling

A form of anti-aliasing used to improve final image quality.  Additional samples are taken for a pixel and the results are averaged.  Exactly where and how these additional samples are taken is controlled by the Passes, Samples, Width, Threshold and Bias settings.

Quality.  An indication of the overall quality to performance ratio the user desires.  Raising the quality may dramatically decrease performance.

Passes.  The number of iterations over an image to be considered.  Each iteration applies the threshold criteria anew.  The specified number of samples is taken for every pixel exceeding the threshold criteria for every pass.

Samples.  If the contrast in adjacent pixels exceeds the threshold value, additional samples will be taken.  This defines the number of additional samples to be taken.  Higher number give better results at the expense of performance.

Pixel Width.  The range in pixles over which to average.  Values typically range from 1.5 to 2.0.

Threshold.  When the contrast ratio between adjacent pixels exceeds this threshold, additional samples will be taken.  This allows optimization of the super sampling process.  Additional samples are not taken in flat, low contrast regions of the image.  A value of zero results in super sampling of every pixel.

Bias.  An indication for the weighting during averaging based upon the sample location.

Jitter.  Enable to apply an initial displacement to make results more noisy- but eliminate discernable patterns in the resulting image.

Filtering.  Enable to filter or smooth textures when magnified.  ‍

• ‍Bilinear.  Sampling considers the nearest 4 pixels.  
• ‍Bicubic.  Sampling considers the nearest 8 pixels.  

Global Illumination

Global Illumination gives you an easy way to enhance the realism of your renders. Global Illumination (GI) simulates the natural behavior of light, bouncing rays from surface to surface to produce photographic quality illumination. It works by calculating more realistic lighting for the scene. Although GI can produce lifelike images, it is disabled by default because it adds to the render time.

GI lets you dramatically improve the realism of images by adding indirect lighting to the scene — normal rendering calculates direct lighting only.

Direct light is light that an object receives directly from light sources. If other objects block the light, the object is in shadow and receives no direct light.

Indirect light is light reflected onto an object by other objects. In nature, almost all objects reflect light. This reflected light gives an object its color — a green apple reflects green light.

Since indirect light will be added using GI, your rendered scene may appear brighter that without GI. You may need to take this brightening into account by reducing the strength you usually use for lights.

Type.  Type of global illumination to apply to the rendering.

• None.  No global illumination calculations will be performed.
• Colored Illumination.  The scene is illuminated as if surrounded by a colored sphere of infinite size.  The color may be specified.  .  Only lighting and occlusion (shadowing) are considered.
• Background Illumination.  The scene is illuminated as if surrounded by a sphere textured with the background image.  This is especially useful with High Dynamic Range (HDR) 3d environment maps that may define areas where light is being emitted.  Only lighting and occlusion (shadowing) are considered.
• Full.  The scene is illuminated as if surrounded by a sphere textured with the background image.  This is especially useful with High Dynamic Range (HDR) 3d environment maps that may define areas where light is being emitted.  Lighting and occlusion (shadowing) are considered.  Additionally, indirect lighting effects are considered giving rise to radiosity and caustics.

Quality.  GI techniques are generally stochastic (based on the average of many random samples).  To increase the quality of the results the number of samples is increased.  The quality setting controls the number of samples that are taken from the illuminating environment.  Higher settings give better results at the expense of performance.  This setting has a dramatic effect on performance.

Power.  The intensity of the global illumination effect.  Higher numbers intensify the effect of lighting form the background.

Caustic Depth.  The maximum number of penetrations that photons may undergo before expiring.  Higher values result in more accurate results at the expense of performance.  Caustics are the effect of indirect light being refracted into patterns that are visible when shined onto adjacent geometry.  A typical example would be the bright spot in the center of the shadow of a semi transparent sphere.  The bright spot is caused by the focusing of light as it is refracted through the sphere.

Radiosity Depth.  The maximum number of bounces that photons may undergo before expiring.  Higher values result in more accurate results at the expense of performance.  Radiosity is the effect of indirect light that is reflected onto adjacent geometry.  A typical example is the color bleeding effect of a red sphere placed next to a white wall.  The wall will appear slightly pink near the sphere.

Irradiance Cache.  A highly useful technique for speeding up GI calculations.  When enabled, calculations are not performed for every image pixel.  Instead, a fraction of the calculations are performed and then averaged.  This dramatically improves performance and may even yield superior, smoother results.

• Shadow Quality.  An indication of how many cache samples to take in areas of shadowing.  Higher numbers give more samples in regions of shadowing—improving shadow appearance at the expense of performance.
• Precision.  The number of pixels per cache sample.  A value of 10 will give approximately one cache sample for every 10 pixels.  Lower values give more accurate results (as the cache samples are located closer together) at the expense of performance.
• Ignore Bump Normal.  This option by default will ignore bump normals which may yield undesirable result when GI is the only source of illumination. Un-check this option for better result. Note: Un-checking this option will can decrease performance with GI.

Photons.  Photons are used to calculate indirect lighting effects.  Indirect light is light that reaches a surface by reflection or refraction.  This is as opposed to direct light, which is the result of being in the direct view of the light.  Indirect lighting is what gives caustics and radiosity.  When enabled, most light sources will emit photons for this purpose.  (Directional lights will not).  Note that lights may have individual GI settings, which override these global values.

• Count.  The number of photons fired from light sources.  The photons are the samples used to approximate the lighting effect.  Higher values give more accurate results at the expense of performance.
• Search Radius.  The radius in which to search for neighboring photon hits.   This is used in conjunction with the Blur setting.  The hits that are found are averaged together to smooth the resulting effect.
• Search Count.  The maximum number of neighboring photon hits to consider.  This is used in conjunction with the Radius setting.  The hits that are found are averaged together to smooth the resulting effect.