NAME
SoVRMLFog -
The SoVRMLFog class is used to specify a global scene fog.
The detailed class documentation is taken verbatim from the VRML97
standard (ISO/IEC 14772-1:1997). It is copyright The Web3D Consortium,
and is used by permission of the Consortium:
SYNOPSIS
#include <Inventor/VRMLnodes/SoVRMLFog.h>
Inherits SoNode.
Public Member Functions
SoVRMLFog (void)
virtual void GLRender (SoGLRenderAction *action)
Static Public Member Functions
static void initClass (void)
Public Attributes
SoSFString fogType
SoSFFloat visibilityRange
SoSFColor color
Protected Member Functions
virtual ~SoVRMLFog ()
Protected Attributes
SoSFBool set_bind
SoSFBool isBound
Detailed Description
The SoVRMLFog class is used to specify a global scene fog.
The detailed class documentation is taken verbatim from the VRML97
standard (ISO/IEC 14772-1:1997). It is copyright The Web3D Consortium,
and is used by permission of the Consortium:
Fog {
exposedField SFColor color 1 1 1 # [0,1]
exposedField SFString fogType "LINEAR"
exposedField SFFloat visibilityRange 0 # [0,inf)
eventIn SFBool set_bind
eventOut SFBool isBound
}
.fi
The Fog node provides a way to simulate atmospheric effects by blending objects with the colour specified by the color field based on the distances of the various objects from the viewer. The distances are calculated in the coordinate space of the Fog node. The visibilityRange specifies the distance in metres (in the local coordinate system) at which objects are totally obscured by the fog. Objects located outside the visibilityRange from the viewer are drawn with a constant colour of color. Objects very close to the viewer are blended very little with the fog color.
A visibilityRange of 0.0 disables the Fog node. The visibilityRange is affected by the scaling transformations of the Fog node’s parents; translations and rotations have no affect on visibilityRange. Values of the visibilityRange field shall be in the range [0, ).
Since Fog nodes are bindable children nodes (see 4.6.10, Bindable children nodes http://www.web3d.org/x3d/specifications/vrml/ISO-IEC-14772-VRML97/part1/concepts.html#4.6.10), a Fog node stack exists, in which the top- most Fog node on the stack is currently active. To push a Fog node onto the top of the stack, a TRUE value is sent to the set_bind eventIn. Once active, the Fog node is bound to the browser view. A FALSE value sent to set_bind, pops the Fog node from the stack and unbinds it from the browser viewer. More details on the Fog node stack can be found in 4.6.10, Bindable children nodes (<http://www.web3d.org/x3d/specifications/vrml/ISO-IEC-14772-VRML97/part1/concepts.html#4.6.10>).
The fogType field controls how much of the fog colour is blended with the object as a function of distance. If fogType is ’LINEAR’, the amount of blending is a linear function of the distance, resulting in a depth cueing effect. If fogType is ’EXPONENTIAL,’ an exponential increase in blending is used, resulting in a more natural fog appearance. The effect of fog on lighting calculations is described in 4.14, Lighting model (<http://www.web3d.org/x3d/specifications/vrml/ISO-IEC-14772-VRML97/part1/concepts.html#4.6.14>).
Constructor & Destructor Documentation
SoVRMLFog::SoVRMLFog (void) Constructor.
SoVRMLFog::~SoVRMLFog () [protected, virtual] Destructor.
Member Function Documentation
void SoVRMLFog::initClass (void) [static] Sets up initialization for data
common to all instances of this class, like submitting necessary
information to the Coin type system.
Reimplemented from SoNode.
void SoVRMLFog::GLRender (SoGLRenderAction * action) [virtual] Action
method for the SoGLRenderAction.
This is called during rendering traversals. Nodes influencing the
rendering state in any way or who wants to throw geometry primitives at
OpenGL overrides this method.
Reimplemented from SoNode.
Member Data Documentation
SoSFString SoVRMLFog::fogType Type of fog. Can be either ’LINEAR’ or
’EXPONENTIAL’. Default value is ’LINEAR’.
SoSFFloat SoVRMLFog::visibilityRange Range of visibility. The distance when
only the fog color can be seen. Default value is (0.0).
SoSFColor SoVRMLFog::color The fog color. Default value is (1, 1, 1).
SoSFBool SoVRMLFog::set_bind [protected] An eventIn that is used to bind
this node (make the node active).
SoSFBool SoVRMLFog::isBound [protected] An eventOut that is sent when the
node is bound/unbound.
Author
Generated automatically by Doxygen for Coin from the source code.