Distance Shader - Revision history

Redmaw: Updated descriptions and added example images.

2021-07-19T23:25:49Z

Updated descriptions and added example images.

Matt at 10:14, 14 March 2012

2012-03-14T10:14:59Z

Matt at 10:01, 14 March 2012

2012-03-14T10:01:58Z

Jo at 05:56, 14 March 2012

2012-03-14T05:56:01Z

Jo at 05:55, 14 March 2012

2012-03-14T05:55:11Z

Jo at 05:47, 14 March 2012

2012-03-14T05:47:28Z

JavaJones at 18:50, 1 June 2011

2011-06-01T18:50:27Z

JavaJones at 17:52, 1 June 2011

2011-06-01T17:52:53Z

JavaJones at 22:55, 31 May 2011

2011-05-31T22:55:41Z

JavaJones: /* Distance Shader */

2011-04-28T20:11:00Z

‎Distance Shader

@@ Line 1: / Line 1: @@
-[[Image:drex_module_144_image_0.png|center|Distance Shader]]
+[[File:DistanceShdr_00_GUI.png|470 px | Distance Shader]]
-'''Node Description and Purpose:'''<br />
+== Overview ==
-The Distance Shader generates colour based on a computation of distance into the scene from a specific camera. You can specify the "near" and "far" colours, and the distances within which the shading will be performed. The two colours are blended between those distances. The output of a Distance Shader can be used to control surface textures, populations, even clouds and other scene features by distance from the camera, allowing you to for example specify that there are no clouds near to the camera and that cloud coverage increases with distance.
+The Distance Shader generates colour by computing the distance between a referenced camera and a given sample point within the scene.  By associating “near” and “far” colours with “near” and “far” distances, you establish a blending range, i.e. a gradient, which can be used to apply colour to a surface or even as a mask for populations, cloud coverage, and surface textures.
-'''Node Type:''' Colour Shader<br />
+*'''Apply near colour: ''' When checked, the colour value defined by the colour swatch to the right, is used at the Near distance.  When unchecked, the shader’s Main input is passed through.
-'''Settings:'''
+*'''Far distance:'''  This value represents the distance in meters from the camera assigned to the Camera setting below.  At this distance the colour defined in the Apply far colour setting is at one hundred percent, and any blending between the Apply near and Apply far colour values will be complete.  Distances beyond this value will take on the Apply far colour.
 <ul>
-<li>
+[[File:DistanceShdr_04_FarDistance.jpg|800 px | Far distance values from 10,000 metres to 100,000 metres.]]
-'''Apply far colour:''' Check this checkbox to use the colour specified at right as the far colour. If you don't specify a colour the shader's input will be passed through.
+</ul>
-</li><li>
-'''Apply near colour:''' Check this checkbox to use the colour specified at right as the near colour. If you don't specify a colour the shader's input will be passed through.
-</li><li>
+*'''Near distance: '''  This value represents the distance in meters from the camera assigned to the camera setting below.  At this distance the colour defined in the Apply near colour setting begins to blend into the Apply far colour, effectively creating a gradient ramp between the two colours.  When they are set to white and black, the shader can be used as a mask with varying degrees of softness or transition zones.  Distance values less than this value take on the Apply near colour value.
 <ul>
-<li>
+{|
-<u>Distance (spherical):</u> This option causes the distances to be calculated in a sphere around the camera. The shape of blending will be circular, radiating out in all directions. Here's an example showing the blend radiating out around the camera:
+|-
-[[image:distance_shader_spherical_example.jpg|180px|thumb|center|Spherical blend example]]
+| [[File:DistanceShdr_05_NearDistance.jpg|800 px | Near distance values from 0 metres to 25,000 metres.  Far distance value = 100,000 metres.]]
-</li><li>
+|-
-<u>Z depth (planar):</u> This option makes the blend happen in the direction the camera is looking. All points from the near distance back past the camera position will take on the near colour and the blend. The blend looks a bit like a line cutting across the scene perpendicular to the camera direction. Here's an example, showing how the blend is oriented to the camera:
+|[[File:DistanceShdr_06_AsMask.jpg|none|400px|By setting the Far and Near colours to white and black, the shader can be used as a mask.]]
-[[image:distance_shader_linear_example.jpg|180px|thumb|center|Planar blend example]]
+|}
 </ul>
-</li><li>
-'''Camera:''' This allows you to choose a camera to use with the shader. You can create cameras which are only used with Distance shaders and not actually used to view the scene through. If you don't specify one the camera being used for rendering is used.
-</li><li>
+*'''Distance mode:''' This popup menu has two options to let you choose the manner in which the distance from the camera is determined.
-'''Clamp far colour:''' When this is checked, all distances greater than the far distance will have the far colour. When it is unchecked, additional colours will be extrapolated beyond the far distance.
+<ul>
-</li><li>
+[[File:DistanceShdr_01_DistanceModes.png|271 px | Distance mode options]] <br /n>
-'''Clamp near colour:''' When this is checked, all distances less than the near distance will have the near colour. When it is unchecked, additional colours will be extrapolated below the near distance.
-</li>
+<u>Distance (spherical):</u> This option causes distances to be calculated in a sphere around the camera. Blending will be circular, radiating out from the camera’s position  in all directions. <br /n>
 </ul>
 [[Category:Colour Shader]]

@@ Line 15: / Line 15: @@
 '''Apply near colour:''' Check this checkbox to use the colour specified at right as the near colour. If you don't specify a colour the shader's input will be passed through.
 </li><li>
-'''Far distance:''' This sets the furthest blending distance. The colour used further out than this distance will be the far colour.
+'''Far distance:''' This sets the furthest blending distance. The colour at this distance will be the far colour.
 </li><li>
-'''Near distance:''' This sets the distance where the near colour starts to blend with the far colour. If this distance is more than 0 the near colour will be used from the camera position to the near distance.
+'''Near distance:''' This sets the distance where the near colour starts to blend with the far colour. The colour at this distance will be the near colour.
 </li><li>
 '''Distance mode:''' This popup allows you choose the way the blending is done. The popup has these options:

@@ Line 11: / Line 11: @@
 <ul>
 <li>
-'''Apply far colour:''' Check this checkbox to use the colour specified at right as the far colour. If you don't specify a colour black will be used.
+'''Apply far colour:''' Check this checkbox to use the colour specified at right as the far colour. If you don't specify a colour the shader's input will be passed through.
 </li><li>
-'''Apply near colour:''' Check this checkbox to use the colour specified at right as the near colour. If you don't specify a colour black will be used.
+'''Apply near colour:''' Check this checkbox to use the colour specified at right as the near colour. If you don't specify a colour the shader's input will be passed through.
 </li><li>
 '''Far distance:''' This sets the furthest blending distance. The colour used further out than this distance will be the far colour.
@@ Line 32: / Line 32: @@
 '''Camera:''' This allows you to choose a camera to use with the shader. You can create cameras which are only used with Distance shaders and not actually used to view the scene through. If you don't specify one the camera being used for rendering is used.
 </li><li>
-'''Clamp far colour:''' When this is checked the far colour is clamped to 1.
+'''Clamp far colour:''' When this is checked, all distances greater than the far distance will have the far colour. When it is unchecked, additional colours will be extrapolated beyond the far distance.
 </li><li>
-'''Clamp near colour:''' When this is checked the near colour is clamped to 0.
+'''Clamp near colour:''' When this is checked, all distances less than the near distance will have the near colour. When it is unchecked, additional colours will be extrapolated below the near distance.
 </li>
 </ul>

@@ Line 37: / Line 37: @@
 </li>
 </ul>
 [[Category:Colour Shader]]

@@ Line 23: / Line 23: @@
 <li>
 <u>Distance (spherical):</u> This option causes the distances to be calculated in a sphere around the camera. The shape of blending will be circular, radiating out in all directions. Here's an example showing the blend radiating out around the camera:
 </li><li>
 <u>Z depth (planar):</u> This option makes the blend happen in the direction the camera is looking. All points from the near distance back past the camera position will take on the near colour and the blend. The blend looks a bit like a line cutting across the scene perpendicular to the camera direction. Here's an example, showing how the blend is oriented to the camera:
 </li>
 </ul>

← Older revision		Revision as of 18:50, 1 June 2011
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−	[[Category:Colour Shader\| ]]	+	[[Category:Colour Shader]]

← Older revision		Revision as of 17:52, 1 June 2011
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−	[[Category:Colour Shader]]	+	[[Category:Colour Shader\| ]]

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 [[Image:drex_module_144_image_0.png|485pxpx|Distance Shader]]
 The Distance Shader generates colour based on a computation of distance into the scene from a specific camera. You can specify the "near" and "far" colours, and the distances within which the shading will be performed. The output of a Distance Shader can be used to control surface textures, populations, even clouds and other scene features by distance from the camera, allowing you to for example specify that there are no clouds near to the camera and that coud coverage increases with distance.
 <!-- imported from file: module_144.html-->