Differential D1044 Diff 3315 manual/composite_nodes/types/vector/map_value.rst

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Standalone View

manual/composite_nodes/types/vector/map_value.rst


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				Map Value Node
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				.. figure:: /images/Tutorials-NTR-ComMapValue.jpg

				Map Value node


				Map Value node is used to scale, offset and clamp values
				(value refers to each vector in the set). The formula for how this node works is:

				Offs
				will add a number to the input value
				Size
				will scale (multiply) that value by a number
				Min/Max
				you can set the minimum and maximum numbers to clamp (cut off) the value too.
				Min and Max must be individually enabled by :kbd:`LMB` clicking on the label for them to clamp.
				:kbd:`Shift-LMB` on the value to change it.


				- If Min is enabled and the value is less than Min, set the ouput value to Min
				- If Max is enabled and the input value is greater than Max, set the ouput value to Max

				This is particularly useful in achieving a depth-of-field effect,
				where you can use the Map Value node to map a Z value
				(which can be 20 or 30 or even 500 depending on the scene) to to range between 0-1,
				suitable for connecting to a Blur node.


				Using Map Value to Multiply values
				==================================

				.. figure:: /images/Manual-Compositing-Map_multiply.jpg

				Using Map Value to multiply


				You can also use the map value node to multiply values to achieve an output number that you
				desire. In the mini-map to the right, the Time node ouputs a value between 0.00 and 1.
				00 evenly scaled over 30 frames. The first Map Value node multiplies the input by 2,
				resulting in an output value that scales from 0.00 to 2.00 over 30 frames.
				The second Map Value node subtracts 1 from the input,
				giving working values between -1.00 and 1.00, and multiplies that by 150,
				resulting in an output value between -150 and 150 over a 30-frame sequence.