XSIBlog

Render optimization: a black art that can make delivering the shot a reality. Rendering special effects, BSP tweaking discussions and the mental-ray engine are some of the subjects you may find in the following articles and posts.

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Most people know you can take a look at what mental ray is currently rendering by pointing imf_disp at a currently rendering frame. Not so many people know that imf_disp is using a well documented feature of mental ray that lets anyone connect to it and read it’’s output as it renders, regardless of whether the render process is local or happening on another machine. The feature is handy for looking at pictures, monitoring the progress of an image as it renders but you can also use it to check whether a render has failed in mid-frame.

Stefano Jannuzzo’s article on Adaptive Occlusion gave me an idea: to control occlusion sampling based on motion samples.
Occlusion techniques can be really fast nowadays for static objects. You can bake it or use Final Gathering occlusion and store it in a Final Gathering Map for example. But with moving objects, those techniques can’t be used.
For [...]

The standard occlusion shaders sample the environment sending out a bunch of rays, and return a color based on the percentage of rays hitting some objects. Mathematically speaking, they integrate the hemisphere (or the cone) centered above the normal with the given number of samples. As we know, a higher sampling rate gives better results, [...]

Let’’s see how it is possible to texture a spot light’’s color based on the angular distance from the spot direction.

Due to the long rendering times involved, most people prefer to perform motion blur as a post process. Here’’s how you can do so with freely available tools.