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Chapter 12: User Interface Mechanisms
Storing Selected Screen Objects
csHit objects hold pointers to objects selected using a variety of mechanisms. The
methods in csHit allow you to access the information held by csHit, including:
• The index number, geomPartNumber, of the triangle, quadrilateral, or polygon inside
a csGeoSet.
• The csGeometry that was intersected.
• The csShape that was intersected.
• The normal in local space at the intersection point. (The space of the geometry that
was intersected.)
• The intersection point in local space. (The space of the geometry that was
intersected.)
• The model view matrix for the csGeometry intersected. The model view is the
concatenation of the viewing matrix and all the matrices in all csTransform objects
above the csShape node.
• The normal in world space at the intersection point. (The space of the camera used
to calculate the hit.)
• The list of nodes leading from the root of the scene graph to the intersected
csGeometry.
• The intersection point in world space. (The space of the camera used to calculate the
hit.)
• Distance of the intersection from the csSeg origin, which is the same as the distance
from the csCamera object.
• The line segment, csSeg, expressed in three dimensions, that was used in the
intersection test.
