Hi Torben,
You said, the view matrix based on the camera manipulator is calculated during the
cull traversal, so the viewmatrix I send during the camera->eventCallback is
the viewmatrix of the last frame.
No, I said the viewer gets the view matrix from the manipulator during
the cull traversal. See the slight difference?
The manipulator's view matrix is calculated any time someone calls its
getMatrix() or getInverseMatrix() method, and it's calculated from the
data it has at that precise moment. The viewer happens to call this
method during the cull traversal. But you could call it during the event
traversal.
You just need to make sure the camera manipulator has all the data it
needs to calculate the right view matrix for the current frame when you
call its getMatrix() or getInverseMatrix() method. i.e. you want it to
have the same information as it will have later during the cull
traversal, so that the result you get is the same as the result the
viewer will get when it calls the same method.
Depending on your manipulator the information it needs will be
different. It processes events during the event traversal, and if it's a
node tracker manipulator it depends on the position of the node it's
tracking being updated too, which might happen in the update traversal
(only you know your whole app so you should know).
Again, placing breakpoints will tell you what's going on. Place one
breakpoint where you call manipulator->getMatrix() or
getInverseMatrix(), one breakpoint in the manipulator's handle() method
(which is called in the event traversal), and another where the viewer
calls getInveseMatrix() on it. Depending on when each of these
breakpoints hits (i.e. 1 then 2 then 3, or 2 then 1 then 3, etc.) you'll
know what state each one is getting. If everything is updated, and then
you call getInverseMatrix() and the viewer calls it right after, you
know both got the same information so you're getting the view matrix for
the right frame.
Hope this clears things up,
J-S
--
______________________________________________________
Jean-Sebastien Guay jean-sebastien.g...@cm-labs.com
http://www.cm-labs.com/
http://whitestar02.webhop.org/
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