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<body class='hmmessage'><div dir='ltr'><font color="#000000" size="2">Dear All,</font><div><font color="#000000" size="2"><br></font></div><div><font color="#000000" size="2">I load a model with the following code in my program, p1 and p2 are osg::Vec3 type variables and simply representing</font></div><div><font color="#000000" size="2">the each ends of object in spatial space ( I also use them to find the direction vector). What I want to achive is: to place </font></div><div><font color="#000000" size="2">that model </font><font color="#000000" size="2">up vector always aligned facing upward ( this doesn't mean that it must coincidence/be parallel with global </font></div><div><font color="#000000" size="2">Z axis) to achieve that If I apply the quaternions then </font><span style="font-size: 10pt;">object is positioned with correct direction vector (calulated via </span></div><div><span style="font-size: 10pt;">p1, p2) but rolled with arbitrary angle along that direction </span><span style="font-size: 10pt;">vector, which violates my conditional goal.</span></div><div><span style="font-size: 10pt;"><br></span></div><div><span style="font-size: 10pt;">It also seems that it's not a supprise that it produces that result bcoz nowhere I specify the crucial right or up vector with </span></div><div><span style="font-size: 10pt;">quaternion which is required to position the object in 3D space. So </span><span style="font-size: 10pt;">How am I supposed to correct that effect either with </span></div><div><span style="font-size: 10pt;">quaternions or matrices ? </span></div><div><font color="#000000" size="2"><br></font></div><div><font color="#000000" size="2"><div> loadedModel = osgDB::readNodeFile("quad.obj");</div><div> osg::Vec3Array* verlist= static_cast<osg::Vec3Array* >(rubber_line->getVertexArray());</div><div> osg::Vec3 p1 = (*verlist)[0];</div><div> osg::Vec3 p2 = (*verlist)[1];</div><div><br></div><div> osg::ref_ptr<osg::PositionAttitudeTransform> Transf = new osg::PositionAttitudeTransform;</div><div> Transf->setPosition( p1 );</div><div><br></div><div> osg::Quat quad;</div><div> osg::Matrix matrix, mat2;</div><div><br></div><div> quad.makeRotate(osg::Vec3(0,1,0),p2-p1);</div><div><br></div><div><span style="font-size: 10pt;"> Transf->setAttitude(quad);</span></div><div> Transf->addChild(loadedModel);</div><div> rootnode->addChild(Transf);</div><div><br></div><div><br></div></font></div> </div></body>
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