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Quality - Sampling and FilteringShading Samples The amount of rays, per pixel, the renderer will trace to perform shading computations. These computations include BRDF sampling, light sampling, subsurface sampling, transparency and any other shading element requested by the Materials. 3Delight uses an adaptive algorithm to automatically select the right shading component to sample, on a per-ray basis. This is the only samples settings necessary for shading sampling setting necessary in 3Delight; there are no per-material, per-light or per-BRDF settings. Note that in 3Delight, surface shading is decoupled to pixel sampling, which allows for a more straightforward control over rendering quality. This is true in most situations as the number of shading samples is usually higher than the number of pixel samples (eg. typically 128 Shading Samples and 32 Pixel Samples). But if you set your Shadings Samples lower than your Pixel Samples, the two are not decoupled anymore as explained here:
Pixel Samples Specifies how many sub-samples pixels each pixel will be subdivided into for anti-aliasing. A draft quality setting for this parameter is 16; could be 16 or lower and a high quality setting could be 64 . Higher values might be needed when and higher (for rendering large motion blur or depth of field). The default value is 9. In 3Delight, screen sampling and surface shading are independent. In other renderers, increasing the amount of "AA" samples will also increase the amount of shading samples, not so in 3Delight. This allows for a more straightforward control over rendering quality.8.
Note that pixel samples also control the quality of such effects as motion blur and depth of field. The images below illustrate the the effect of pixel samples on a moving object.
Volume Samples Controls the quality of volume rendering. This is the only quality control as there is no per-light or per-object quality parameters in 3Delight.
Pixel Filter These two parameters select the shape and the size of the screen pixel filter. The available filter shape are : blackman-harris, gaussian, mitchell, catmull-rom, sinc, box and triangle. We recommend to use the gaussian blackman-harris pixel filter with a filter width of 2 3 as this will produce optimal quality. Note: A larger filter width implies a slightly slower filtering process. And enlarging some filters beyond 2, such as the ‘gaussian’ or ‘box’, will blur the result and not increase the quality. On the other hand, some filters do not work well with small width values. This is the case for mitchell, catmull-rom and sinc filters for which it is suggested to specify a width of 4 or more.
Quality - High Intensity HandlingHigh pixel intensities out of the shading calculation can be undesirable and create visual artefacts. This can happen in images with visible light sources and images with “hot spots” due to intense specular highlights. The following options enables additional processing on final pixel colours in order to bring high values into displayable range. High Intensity Handling Selects the method to handle high intensity pixels: | ||||||||||||||||||||||
OFF | Pixels are left untouched after shading calculation. | |||||||||||||||||||||
Clamp | This method simply clamps image pixels to High Intensity Point. The final image will only contain pixels in the range [0..High Intensity Point]. | Compress | This method uses non-linear mapping to compress pixels values in the range of [0..High Intensity Point] to the range [0..1]. With this method, Maximum Value is used as a white point and pixel values larger than High Intensity Point will not be clamped. This allows to preserve additional head room if needed (for example to apply post-processing operators such as glow)
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Quality - Maximum Ray Trace Depths
Max Diffuse Depth
Sets the maximum bounce depth a diffuse ray can have. Diffuse bounces are counted each time a ray hits a diffuse surface.
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Max Reflection Depth
Sets the maximum bounces a reflected ray can reach. Reflection occurs when a ray bounces in the same hemisphere as the surface normal. Reflection rays include both mirror reflection and soft reflections due to rough surfaces. Setting this value to 0 will disable reflections.
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Max Refraction Depth
Sets the maximum bounces a refracted ray can reach. Refraction occurs when a ray bounces in the opposite hemisphere of the surface normal. Refraction rays include hard refraction and soft refracton due to rough surfaces.
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Max Hair Depth
Sets the maximum bounce depth a hair ray ray can have. Hair bounces are counted each time a ray hits another hair (that is a surface with a Hair and Fur material applied). Note that hair are akin to volumetric primitives and might need elevated ray depth to properly capture the illumination.
Max Distance
This sets the maximum distance a ray can travel in the scene. If no objects are hit within that distance the ray will only return illumination from light sources (including environment).
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