Re: [osg-users] Is it safe/ok to use only PositionAttitudeTransforms instead of MatrixTransforms
Hi Alji, I did end up using MatrixTransforms and the one place where I found them easier to use (i.e. more logical to achieve the functionality) was where I had to apply simultaneous rotations around X, Y and Z axes. Thanks again. Sincerely, Sanat -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=42037#42037 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Is it safe/ok to use only PositionAttitudeTransforms instead of MatrixTransforms
Hi, If you are articulating some objects, like Robot arm, you rather use MT. for instance a rotation of a joint imply rotation of the rest of the arm, rather then computing the Position of each part , you construct a hierarchy of MTs and Multiplying one MT by another apply the change on the rest of the part ... I advice you to make a look at OpenSceneGraph Example osgRobot. Have a nice weekend Mohamed ALJI -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=41271#41271 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Is it safe/ok to use only PositionAttitudeTransforms instead of MatrixTransforms
Hi Alji, Thanks for your reply. Though I am not sure if I follow your post entirely: rotation of a joint imply rotation of the rest of the arm, rather then computing the Position of each part , you construct a hierarchy of MTs and Multiplying one MT by another apply the change on the rest of the part ... But isn't this the same behavior as having a chain of PATs where modifying one transform node's position/attitude affects all the nodes downstream? Are you implying that it is easier to apply rotations to a series of MT than it is to a similar PAT hierarchy? Thanks, Sanat -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=41274#41274 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Is it safe/ok to use only PositionAttitudeTransforms instead of MatrixTransforms
Hi nerazzuri,
[quote=nerazzuri]But isn't this the same behavior as having a chain of PATs
where modifying one transform node's position/attitude affects all the nodes
downstream? [/quote]
the same functionnality but you will have to specify a value rather then
multiplying.
[quote=nerazzuri]Are you implying that it is easier to apply rotations to a
series of MT than it is to a similar PAT hierarchy?
[/quote]It is not question of easier or not. First, it depends on the context,
both PositionAttitudeTransform MatrixTransform can do the same stuffs. Except
that, when you use a PAT, you are, kind of setting, values {_position,
_attitude, _scale, _pivotPoint}. On the other hand, MT encapsulates a Matrix
and using preMult or postMult will implicitly do the job for you.
It is by practice and intuition, you figure out the right Transform to use.
Maybe I can help more if you tell me more details on how you want to use them.
Cheers
Mohamed ALJI
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http://forum.openscenegraph.org/viewtopic.php?p=41276#41276
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