Autodesk 12812-051462-9011 User Guide 3 - Page 902

In general, you can get good, fairly quick results with a lower Filter Size value as long as Rays/Sample has a high value and Adaptive Undersampling is on. Other Tips for Using the Light Tracer ■ To improve rendering time, use the Object Properties dialog on page 305 to disable light tracing (or radiosity solving) for objects that don't have a great impact on the final effect. TIP You can also use the Advanced Lighting Override material on page 5734 to alter the effect of light tracing on particular objects. For example, if you encounter visual artefacts with a bump-mapped material, convert it to an Advanced Lighting Override material and reduce the Indirect Light Bump Scale value. ■ Experiment with the Adaptive Undersampling group settings, which restrict light tracing to the areas of your scene that need it. ■ To increase the amount of color bleeding, increase the values of both Bounces and Color Bleed. Color bleeding is usually a subtle effect. ■ If there are glass objects in the scene, increase the Bounces value to an amount greater than 0. But be aware that this increases rendering time. ■ If the main scene lighting is a Skylight on page 5065, and you need specular highlights in your scene, add a second light: for example, a Directional light that parallels the Skylight. Make sure Shadows are turned on for this light, and on the light's Advanced Effects rollout on page 5108, turn off Diffuse. If the objects with highlights don't greatly affect shadows or color bleeding, you can leave Diffuse on for this light, and use Object Properties to exclude the objects from light tracing. ■ Set Key filters are not taken into account when you animate Light Tracer settings. If you wish to use Set Key to create keys for animating the Light Tracer parameters, Shift+right-click the spinner to create those keys. IMPORTANT If you use a texture map with the Skylight, you should use an image-processing program to thoroughly blur the map before using it. This helps reduce variance and the number of rays needed for light tracing. You can blur the map beyond recognition, and it will still look correct when used for regathering. Default Scanline Renderer Controls | 6157