mynodelic opened this issue on Jun 07, 2010 · 12 posts
ShawnDriscoll posted Mon, 07 June 2010 at 8:05 PM
Don't remember where I found this from. Have not tried it yet:
How to reduce flickering and/or noise in animations:
Introducing the Texture Filtering render setting!
Texture Filtering is an essential render setting to reduce noise and flickering that can arise because of high frequency textures (components of materials that exhibit very fine detail, usually finer than the size of a pixel). When used properly, it will lower the needs for strong object anti-aliasing (thus speeding up the render), and greatly reduce texture flickering.
Where to find it:
It can be accessed via the anti-aliasing options dialog, just above texture anti-aliasing options. This setting is always accessible, even for render presets. Its value is editable through a slider that ranges from 0 to 100%.
How it works:
This value corresponds to the size of the filter applied over textures during render. Ideally, this filter should always have the size of a pixel, so that all texture detail contained in each pixel is properly taken into account during texture evaluation. This corresponds to a value of 50% for Texture Filtering. If you specify a lower value, textures will be sharper but with more noise and/or flickering. If you specify a higher value, noise will be smoothed out but textures will appear blurred.
In practice:
You should tweak the value regarding your specific needs. In practice, the smallest value that yields good-enough results should be used. From our own experience, a default value of 33% usually does the trick.
Texture Filtering will influence two components at render:
Bitmaps: for each bitmap used in materials, if you edit its texture map node via the function editor, you will see a flag named "allow mip-mapping", which is checked by default. When this flag is checked, and if Texture Filtering has a non zero value, corresponding bitmaps will be pre-filtered just before rendering. Thus, at render time, distant bitmaps won't exhibit any noise or flickering. This is particularly useful when rendering animated plants, especially for distant ones. You will enjoy much smoother results, and a great reduction in flickering. As specified above, a value for Texture Filtering of 33% will generally produce the best results.
Generic texture anti-aliasing: when texture anti-aliasing is enabled, the Texture Filtering value will drive the size of the filter used by the texture anti-aliasing process, just like for bitmaps. This is very important because if texture anti-aliasing is enabled but Texture Filtering is set to 0%, you won't notice any improvement. Just like for bitmaps, a value of 33% is generally ideal for Texture Filtering used along with texture anti-aliasing.