Differential D1034 Diff 3266 manual/composite_nodes/types/filter/blur_node.rst

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Standalone View

manual/composite_nodes/types/filter/blur_node.rst


				.. TODO/Review: {{review\|copy=X}} .

				Blur Node
				=========

				.. figure:: /images/Tutorials-NTR-ComBlur.jpg

				Blur node


				The Blur node blurs an image, using one of seven blur modes
				(set using the upper-left popup button), and a radius defined by the X and Y number buttons.
				By default these are set to zero,
				so to enable the node you must set one or both to a value greater then 0.
				You can optionally connect a value image to the Size input node,
				to control the blur radius with a mask.
				The values must be mapped between 0-1 for best effect,
				as they will be multiplied with the X and Y number button values.


				Options
				-------

				The X and Y values are the number of pixels over which to spread the blur effect.

				The Bokeh button (only visible as Bok or Bo on some screen setups)
				will force the blur node to use a circular blur filter. This gives higher quality results,
				but is slower then using a normal filter. The Gam button (for "gamma")
				makes the Blur node gamma-correct the image before blurring it.


				.. figure:: /images/Tutorials-NTR-ComBlurIllustration.jpg
				:width: 650px
				:figwidth: 650px

				Blur node blur modes using 15% of image size as XY, no Bokeh/Gamma. Click expand to see details


				The difference between them is how they handle sharp edges and smooth gradients and preserve
				the highs and the lows.
				In particular (and you may have to closely examine the full-resolution picture to see this):

				Flat
				Simply blurs everything uniformly
				Tent
				Preserves the high and the lows better making a linear falloff
				Quadratic
				CatRom keeps sharp-contrast edges crisp.
				Cubic, Mitch
				Preserve the highs but give almost a out-of-focus blur while smoothing sharp edges


				Example
				-------

				An example blend file, in fact the one used to create the image above,
				`is available here. <http://wiki.blender.org/index.php/Media:Manual-Node-Blur.blend>`__
				The .blend file takes one image from the RenderLayer "Blurs" and blurs it while offsetting it (Translate)
				and then combining it (AlphaOver) to build up the progressive sequence of blurs.
				Play with the Value and Multiply nodes to change the amount of blurring that each algorithm does.
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