About the Interactive Ray Tracing tab of the Performance and Quality window

These controls are available in the Interactive Ray Tracing tab of the Performance and Quality window.

Interactivity slider

Drag to the left to increase frame rate and allow smoother interactivity with the scene. Drag to the right to increase visual quality of the scene. Frame rate and, potentially, interactivity will decrease. Experiment with different settings by orbiting in the scene until you find a setting that works for you. Generally, lower values are better for complex scenes, while higher values are fine for simpler scenes. Available values range from one to 100.

Quality preset

Select from default presets or ones you create. Each preset sets the values in the rest of the window. Usually, Ambient Shadow - Interactive provides settings that will work well in most scenes. If you make changes to the settings in the rest of the window, a star (*) appears beside the preset name to indicate that its values have been changed. You can save the settings to a new preset using the Save Preset As button at the bottom of the window.

Lighting Mode

Choose between Basic (ambient occlusion) and Advanced (global illumination) to set lighting for the scene. Basic is the faster choice, while Advanced has better quality in certain situations; for example, in scenes where light falls in from a window.

Render Shadows

Turn shadows on or off.

Advanced Settings: Desired Trace

Sets the number of times a ray bounces. A higher setting may impact performance, but provides more bounces, more reflections, and better visual accuracy. For example, with a transparent material like glass, you’ll see more detail behind the glass. For reflective surfaces, you will see better reflections; for example, on a windshield, a setting of 1 shows a reflection of the sky, but a setting of 2 shows some of the geometry that is part of the scene.

Use a value as low as you can while maintaining good visual quality. Available values are 1 to 99, but usually 5 or so is adequate.

Advanced Settings: Precision

Use to enable more accurate visuals (better edges). Available values are 0 and 1.

Advanced Settings: Sharpening filter

Select an oversampling filter from the drop-down box to choose how sharp the image should be.

Sampling is an antialiasing technique. It provides an estimated color for each rendered pixel. The renderer first samples the scene color at locations within the pixel or along the edge of the pixel, then uses a filter to combine the samples into a single pixel color. The sharper, the slower.

Box, the default, is also the quickest and combines samples evenly, without weighting them. Mitchell is often the most accurate. The other filters use their own particular curves to weigh samples before combining them.

Algorithms in order of sharpness are:

• Box
• Triangle
• Gaussian
• Mitchell
• Lanczos

Advanced Settings: Filter Width and Filter Height

These boxes set the pixel dimensions of the area to be computed when sharpening; for example, if you enter values of 3 in both boxes, a 3 x 3 box is used. The smaller the area, the sharper the image. Use as small an area as you can while maintaining visual fidelity without impacting performance.

Advanced Settings: Use precalculated ambient shadows

If selected, precalculated shadows are displayed when present. See Apply ambient shadows. Precalculated ambient shadows override ray tracing ambient shadows when this is selected.

Refine Image

Choose one of the following options for rendering durations:

• Render Levels: Enter a value to control exactly how much to render the scene. This value will be used no matter what computer is used to open the scene, so you will always have the same quality level.
• Minutes: For more complex scenes, enter a time duration for rendering.
• Forever: For really complex scenes with global illumination, select this to render for an open-ended period of time until the image looks the way you want it to, at which point you can publish the image.

Save Preset As

Save the settings in the Interactive Ray Tracing tab of the Performance and Quality window as a preset. This is a good way to preserve temporary modifications to other presets (denoted by a * in front of the name), or to create presets based on computer capabilities or special needs.

By default, Showcase sets the save folder as \Documents\Autodesk Showcase 2014\InteractiveRaytracingSettings\. Preset files saved to this location are automatically available to you in the Quality preset drop-down box near the top of the window, as well as the Publish window. Presets saved to other locations will not be loaded by Showcase unless they are moved to the default location.

To share a custom preset with another Showcase user, copy the XML file to their InteractiveRaytracingSettings folder.