Added comment to osg::Transform w.r.t use of GL_NORMALIZE when using

scaling Transforms.
This commit is contained in:
Robert Osfield 2001-12-29 14:27:46 +00:00
parent 460a78b454
commit 625e8e730a

View File

@ -11,9 +11,17 @@
namespace osg {
/** Transform - is group which all children
are transformed by the the Transform's osg::Matrix. Typical uses
of the Transform is for positioning objects within a scene or
producing trakerball functionality or for animation.
* are transformed by the the Transform's osg::Matrix. Typical uses
* of the Transform is for positioning objects within a scene or
* producing trackball functionality or for animation.
* Note, if the transformation matrix scales the subgraph then the
* normals of the underlying geometry will need to be renormalized to
* be unit vectors once more. One can done transparently through OpenGL's
* use of either GL_NORMALIZE and GL_SCALE_NORMALIZE modes. Further
* background reading see the glNormalize documentation in the OpenGL Reference
* Guide (the blue book). To enable it in the OSG, you simple need to
* attach a local osg::StateSet to the osg::Transform, and set the appropriate
* mode to on via stateset->setMode(GL_NORMALIZE,osg::StateAttribute::ON);.
*/
class SG_EXPORT Transform : public Group
{
@ -30,12 +38,12 @@ class SG_EXPORT Transform : public Group
STATIC
};
/** Set the Transform Type, which can be DYNAMIC - the Marix
* value is updated duing the main loop, or STATIC - the Matrix
* is constant throughut the life of the main loop. STATIC
/** Set the Transform Type, which can be DYNAMIC - the Matrix
* value is updated during the main loop, or STATIC - the Matrix
* is constant throughout the life of the main loop. STATIC
* Transforms can be optimized away is some instances, which
* can improve performanc so unless you plan to modify the
* Matrix explicity set the Matrix to STATIC. The default
* can improve performance so unless you plan to modify the
* Matrix explicitly set the Matrix to STATIC. The default
* value is DYNAMIC.*/
inline void setType(Type type) { _type = type; }