Color Bleed (Bounced Color) and Material Saturation

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Color Bleed (Bounced Color) and Material Saturation

Post by Fletch » Mon Feb 16, 2015 9:59 am

Color Bleed (Bounced Color) and Material Saturation

Color Bleeding, the bouncing of color from one surface onto an adjacent surface, is best controlled by building materials correctly. Fully saturated colors will result in rendering artifacts and longer render times because they are bouncing more light and color than they should in the real world.

Color saturation can be very quickly and easily controlled using the SATURATION color slider in SketchUp's Material Editor. Or if using the HSB (Hugh Saturation Brightness) mode of color editing in the SketchUp Material Editor, try dragging S (saturation) AND/OR the B (Brightness) slider down.

First, Set basic brightness for materials (paints, plastic, wood, stone) at 80% or less, maximum of absolutely brightest color should not exceed 90%, but almost all architectural materials should be 70%-80%. Think of it this way - the color in your model should be the color of the material you desire when it is under cloudy flat light, not in sunlight. It needs room for the sun-light to be able to brighten it up... if you set it to begin with at 100% brightness, how can it get any brighter in the sun or under lights? Same with dark colors, if you set black to full black, how can any shadow fall upon the surface? It needs room to get darker in shadow. Changing Saturation is not as effective to reduce color bleeding compared to reducing Brightness

Fully saturated colors do not exist in real life. It's typical in magazines to have colors over-saturated. It is not uncommon to see an increase of 30% saturation over real life colors. If you desire saturated colors, increase saturation of entire image in post-production/post-processing.

For rendering, build your materials to be real-world color appropriate. If you find your colors bouncing too much onto adjacent surfaces, it's likely that the colors of your materials are not correct.

If you work on a laptop, they have notoriously high gamma and low saturation screens, so often to compensate people will tend to bump up the brightness of their materials colors. This will result in color artifacts and longer render times because the materials are no longer physically accurate.

It is very important when rendering to have a properly calibrated computer monitor/screen/display. Subject: Calibrate your Monitor Step-by-Step test
ColorBleed-MaterialBrightness.jpg (501.73 KiB) Viewed 5434 times
ColorBleed-MaterialSaturation.jpg (641.95 KiB) Viewed 5434 times

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Re: Color Bleed (Bounced Color) and Material Saturation

Post by JGA » Tue Feb 17, 2015 1:58 pm


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