![]() |
http://www.sim.no/ http://www.coin3d.org/ |
The SoCullElement class is used internally for render and pick culling.The element holds all planes the geometry should be inside, and keeps a bitflag to signal which planes need to be tested. More...
#include <Inventor/elements/SoCullElement.h>
Public Member Functions | |
virtual void | init (SoState *state) |
virtual void | push (SoState *state) |
virtual SbBool | matches (const SoElement *elt) const |
virtual SoElement * | copyMatchInfo (void) const |
Static Public Member Functions | |
static void | initClass (void) |
static void | setViewVolume (SoState *state, const SbViewVolume &vv) |
static void | addPlane (SoState *state, const SbPlane &newplane) |
static SbBool | cullBox (SoState *state, const SbBox3f &box, const SbBool transform=TRUE) |
static SbBool | cullTest (SoState *state, const SbBox3f &box, const SbBool transform=TRUE) |
static SbBool | completelyInside (SoState *state) |
Protected Member Functions | |
virtual | ~SoCullElement () |
The SoCullElement class is used internally for render and pick culling.
The element holds all planes the geometry should be inside, and keeps a bitflag to signal which planes need to be tested.
This element is an extension for Coin, and is not available in the original Open Inventor.
The maximum number of planes in this element is 32, which should be more than enough, since the view frustum is represented by 6 planes, and the maximum number of OpenGL clipping planes is typically 6 or 8.
This element is designed for fast culling, and will not do optimal view frustum culling; a box might not be culled even though it is outside the view frustum. The assumption is that the view frustum is small compared to the world model. The element simply records all planes to be culled against, and the graph is not culled until it is completely outside one of the planes.
SoCullElement is not active for other actions than SoGLRenderAction. It's possible to enable it for SoCallbackAction by updating it in a post camera callback though. Do something like this:
static SoCallbackAction::Response camera_cb(void * data, SoCallbackAction * action, const SoNode * node) { SoState * state = action->getState(); SoCullElement::setViewVolume(state, SoViewVolumeElement::get(state)); return SoCallbackAction::CONTINUE; } [...] SoCallbackAction cba(myviewport); cba.addPostCallback(SoCamera::getClassTypeId(), camera_cb, NULL);
When the view volume is set in SoCullElement in the post camera callback, SoCallbackAction will perform culling on Separators and other nodes in the same way as SoGLRenderAction.
SoCullElement::~SoCullElement | ( | ) | [protected, virtual] |
The destructor.
void SoCullElement::initClass | ( | void | ) | [static] |
Initialize relevant common data for all instances, like the type system.
Reimplemented from SoElement.
void SoCullElement::setViewVolume | ( | SoState * | state, |
const SbViewVolume & | vv | ||
) | [static] |
Sets the current view volume. In effect, this adds six planes to the list of culling planes. If a view volume has already been set, the old view volume planes are overwritten by the new ones. The view volume must be in the world coordinate systems.
Add plane geometry must be inside. The plane must be in the world coordinate system.
SbBool SoCullElement::cullBox | ( | SoState * | state, |
const SbBox3f & | box, | ||
const SbBool | transform = TRUE |
||
) | [static] |
Cull against box. If transform is TRUE
, the box is assumed to be in object space, and will be transformed into world space using the model matrix. Returns TRUE
if box is outside one of the planes, and updates the element to detect when geometry is completely inside all planes.
SbBool SoCullElement::cullTest | ( | SoState * | state, |
const SbBox3f & | box, | ||
const SbBool | transform = TRUE |
||
) | [static] |
Cull against box. If transform is TRUE
, the box is assumed to be in object space, and will be transformed into world space using the model matrix. Returns TRUE
if box is outside one of the planes. This method will not update the element state, just perform a cull test against active planes.
SbBool SoCullElement::completelyInside | ( | SoState * | state | ) | [static] |
Returns TRUE
if the current geometry is completely inside all planes. There is no need to do a cull test if this is the case.
SoElement * SoCullElement::copyMatchInfo | ( | void | ) | const [virtual] |
This function creates a copy of the element that contains enough information to enable the matches() function to work.
Used to help with scenegraph traversal caching operations.
Implements SoElement.
Copyright © 1998-2010 by Kongsberg Oil & Gas Technologies. All rights reserved.
Generated for Coin by Doxygen 1.7.3.