Inventor/oivDepthPeeling_frag.h File Reference

This file contains fonction that should be used to correctly manage transparency in custom shaders. More...

Go to the source code of this file.

Defines
#define	OIV_DEPTHPEELING_H
Functions
bool	OivDepthPeel (vec3 fragmentCoords)
void	OivDepthPeelingOutputColor (vec4 color)
void	OivDepthPeelingOutputColor (vec4 color, vec3 coords)

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Detailed Description

This file contains fonction that should be used to correctly manage transparency in custom shaders.

To properly handle transparency, your fragment shader should contains the following function calls:

• You should enclose your code in if ( OivDepthPeel(gl_FragCoord.xyz) ) { } condition
• You should output your color using OivDepthPeelingOutputColor() method

These methods are accessible by including the <Inventor/oivDepthPeeling_frag.h> header in your shader:

Ex:

 void main()
 {
   if ( OivDepthPeel(gl_FragCoord.xyz) )
   {
     Vec4 color = vec4(1, 0, 0, 0.5);
     OivDepthPeelingOutputColor(color);
   }
 }

Definition in file oivDepthPeeling_frag.h.

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Define Documentation

#define OIV_DEPTHPEELING_H

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Function Documentation

bool OivDepthPeel

(

vec3

fragmentCoords

)

This method peels the current fragment.

If the fragment must be ignored the method does the discard. The fragments coords must be in screen space (gl_FragCoord.xyz should always be used)

Returns true if the fragment should be shaded.

void OivDepthPeelingOutputColor	(	vec4	color,
		vec3	coords
	)

By default the depth generated by the rasterizer (gl_FragCoord.z) is used but some algorithms may modify the depth in the fragment shader.

In theses case gl_FragCoord.z is not valid and thus the user-defined depth coordinate must be explicitly specified

void OivDepthPeelingOutputColor

(

vec4

color

)

When depth peeling is enabled OivDepthPeelingOutputColor must be called instead of using the gl_FragData[0] since some depth peeling techniques use MRTs (multiple render targets) or premultiply the color by the alpha value (on-the-fly blending for example).