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6.2.2 LOCAL_ATTR (a1, a2, ...)
A group of attributes ai which is used with the following rules
when the scene graph is rendered:
When the scene graph is traverted, each scene graph node
gets a structure with the currently active attributes
from its parent, and a structure with overwrite attributes.
The scene graph nodes makes two copys of the
active attributes struct. The first copy will be used when
the primitives attached to the scene graph node itself
get rendered, the second copy will be passed to the child
scene nodes.
It also makes a copy of the overwrite attributes struct,
which will be passed to the child scene nodes too.
Then happens the following:
- The attributes set with ATTRIBS (see 6.2.1)
are applied to both copys
of the active attributes struct.
- The attributes set with LOCAL_ATTR are only applied to
the copy which is used by the scene graph node itself when it renders
its own primitives (i.e. this has no influence to the child scene nodes)
- Then the attributes set with OVWRT_ATTR (see 6.2.3)
are applied to both
copys of the active attributes, and to the copy of the overwrite
attributes struct.
- Then the scene graph node renders its own primitives with the
first copy of the active attributes struct,
afterwards it calls its child scene graph nodes with the second copy
of the active attributes struct and the copy of the overwrite
attributes struct.
The ai must be attribute type nodes.
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2002-01-20