Dot Product - Revision history

Redmaw: Updated descriptions and added example images.

2022-03-02T01:04:17Z

Updated descriptions and added example images.

JavaJones at 18:37, 1 June 2011

2011-06-01T18:37:16Z

JavaJones at 01:30, 18 May 2011

2011-05-18T01:30:00Z

Jo: /* Dot Product */

2011-05-09T06:19:16Z

‎Dot Product

JavaJones at 01:32, 28 April 2011

2011-04-28T01:32:19Z

127.0.0.1: jrfconvert import

2010-07-11T02:55:05Z

jrfconvert import

New page

[[Category:IMPORT]]
='''Dot Product'''=

[[Image:drex_module_73_image_0.png|485pxpx|Dot Product]]
__NOTOC__

@@ Line 1: / Line 1: @@
-[[Image:drex_module_73_image_0.png|485pxpx|Dot Product]]
+<div style="float:right; border-style:solid; padding:20px"><categorytree mode=pages hideroot=off>Multiply</categorytree></div>
-<!-- imported from file: module_73.html-->
+[[File:DotProduct_00_GUI.png|none|470px|Dot Product]]
-'''Node Description & Purpose: '''<br /> The Dot product node takes the Input and Input 2 vectors and outputs the dot product of the two vectors, which is a scalar value. The dot product is the cosine of the angle between the two vectors multiplied by the lengths of the two vectors.
 The dot product is useful because it can tell us about the relationship between two vectors. If the dot product equals 0 then the two vectors are at 90º to each other (perpendicular). If the dot product is greater than 0 then two vectors are pointing roughly in the same direction. If the dot product is less than 0 then the two vectors are pointing away from each other.
-The dot product is even more useful when the two vectors are unit vectors. In that case the dot product is the cosine of the angle between the two vectors. You can also get the cosine of the angles between non-unit vectors using the following formula:
+The dot product is even more useful when the two vectors are unit vectors. In that case the dot product is the cosine of the angle between the two vectors. You can also get the cosine of the angles between non-unit vectors using the following formula: <br /n>
 <code>cosine = Dot product( vector 1, vector 2 ) ÷ ( Length( vector 1 ) x Length( vector 2 ) )</code>
 The cosine value will range between 1 and -1. If the two vectors are pointing in the same direction the value will be 1. If they're at right angles to each other the value will be 0. If one vector is pointing in exactly the opposite direction to the other vector (i.e. 180º to the other vector) the value will be -1.
-To find the actual angle between the vectors in degrees you can do this:
+To find the actual angle between the vectors in degrees you can do this: <br /n>
-<br />
+You can further manipulate the mask created by Dot Product node by connecting its output to a Colour Adjust node, then adjusting the Black point and White point parameters.  This provides a method for controlling the opacity of the mask.
-'''Settings: '''<br />
+<br /n>
 [[Category:Multiply]]

← Older revision		Revision as of 18:37, 1 June 2011
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	This node has just the one setting, which lets you choose a node for Input 2.		This node has just the one setting, which lets you choose a node for Input 2.

−	[[Category:Multiply\| ]]	+	[[Category:Multiply]]

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-[[Category:IMPORT]]
+[[Image:drex_module_73_image_0.png|485pxpx|Dot Product]]
 <!-- imported from file: module_73.html-->
@@ Line 26: / Line 23: @@
 '''Settings: '''<br />
 This node has just the one setting, which lets you choose a node for Input 2.

← Older revision		Revision as of 06:19, 9 May 2011
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	<!-- imported from file: module_73.html-->		<!-- imported from file: module_73.html-->

−	'''Node Description & Purpose: '''<br /> The Dot product node takes the Input and Input 2 vectors and outputs the dot product of the two vectors, which is a scalar value. The dot product is the cosine of the angle between the two ~~input~~ vectors.<br /><br />'''Node Type: ''' Function<br /><br />'''Settings: '''<br /> This node has just the one setting, which lets you choose a node for Input 2.	+	'''Node Description & Purpose: '''<br /> The Dot product node takes the Input and Input 2 vectors and outputs the dot product of the two vectors, which is a scalar value. The dot product is the cosine of the angle between the two vectors multiplied by the lengths of the two vectors.
		+
		+	The dot product is useful because it can tell us about the relationship between two vectors. If the dot product equals 0 then the two vectors are at 90º to each other (perpendicular). If the dot product is greater than 0 then two vectors are pointing roughly in the same direction. If the dot product is less than 0 then the two vectors are pointing away from each other.
		+
		+	The dot product is even more useful when the two vectors are unit vectors. In that case the dot product is the cosine of the angle between the two vectors. You can also get the cosine of the angles between non-unit vectors using the following formula:
		+
		+	<code>cosine = Dot product( vector 1, vector 2 ) ÷ ( Length( vector 1 ) x Length( vector 2 ) )</code>
		+
		+	The cosine value will range between 1 and -1. If the two vectors are pointing in the same direction the value will be 1. If they're at right angles to each other the value will be 0. If one vector is pointing in exactly the opposite direction to the other vector (i.e. 180º to the other vector) the value will be -1.
		+
		+	To find the actual angle between the vectors in degrees you can do this:
		+
		+	<code>angle in degrees = Radians to degrees( Arccos( cosine ) )</code>
		+
		+	<br />
		+
		+	'''Node Type: ''' Function<br /><br />
		+
		+	'''Settings: '''<br />
		+	This node has just the one setting, which lets you choose a node for Input 2.

← Older revision		Revision as of 01:32, 28 April 2011
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	__NOTOC__		__NOTOC__
	<!-- imported from file: module_73.html-->		<!-- imported from file: module_73.html-->
		+
		+	'''Node Description & Purpose: '''<br /> The Dot product node takes the Input and Input 2 vectors and outputs the dot product of the two vectors, which is a scalar value. The dot product is the cosine of the angle between the two input vectors.<br /><br />'''Node Type: ''' Function<br /><br />'''Settings: '''<br /> This node has just the one setting, which lets you choose a node for Input 2.