Re: [osg-users] Draw line in 3D screen
Hi, Thks Robert and Shayne I solve my problem with your direction. Cheers, Lalit -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=44767#44767 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Draw line in 3D screen
Hi Lalit, In the past I've tackled problems like drawing from mouse coords into 3D by creating a ray from the mouse coords and then intersecting this with a plane. The maths for computing the intersection point can be handled by the osg::Plane class, there is no need to use the high level scene graph intersection routines. For you application only you will be able to answer how you want to constrain the points you want to generate - would a plane that is orthogonal to the image plane and going through the mid point of the data cloud be appropriate? You'll need to decide yourself what is appropriate. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Draw line in 3D screen
Dear Robert: Thanks for input. I am trying to re-phrase my question. I have loaded a 3D data (X,Y,Z) on screen and can see these points as in screenshot_1. Also, I can, using mouse, draw line through these points (also shown.) However, if I want to draw a line as shown in screenshot_2, I am not able to do this, as this line does not passes through any loaded data. What can be the procedure to draw these lines using mouse which are not passing through any data point. Thank you! Cheers, Lalit -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=44707#44707 Attachments: http://forum.openscenegraph.org//files/screenshot_2_123.jpg http://forum.openscenegraph.org//files/screenshot_1_443.jpg ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Draw line in 3D screen
In the absence of existing data, what are your constraints for drawing these lines in 3D? Can they be coplanar in 3D space? From your description, it sounds like you're drawing a line with the mouse using 3D picking on existing points in 3D. Is this correct? -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Lalit Manchwari Sent: Monday, January 09, 2012 5:50 AM To: osg-users@lists.openscenegraph.org Subject: Re: [osg-users] Draw line in 3D screen Dear Robert: Thanks for input. I am trying to re-phrase my question. I have loaded a 3D data (X,Y,Z) on screen and can see these points as in screenshot_1. Also, I can, using mouse, draw line through these points (also shown.) However, if I want to draw a line as shown in screenshot_2, I am not able to do this, as this line does not passes through any loaded data. What can be the procedure to draw these lines using mouse which are not passing through any data point. Thank you! Cheers, Lalit -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=44707#44707 Attachments: http://forum.openscenegraph.org//files/screenshot_2_123.jpg http://forum.openscenegraph.org//files/screenshot_1_443.jpg ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.or g ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Draw line in 3D screen
Dear Shayne
I use polytope to pick the 3D coordinate of data.
……..
osg::ref_ptrosgUtil::PolytopeIntersector picker;
picker = new osgUtil::PolytopeIntersector(osgUtil::Intersector::WINDOW, x-w,
y-h, x+w, y+h );
osgUtil::IntersectionVisitor iv( picker );
viewer-getCamera()-accept( iv );
if(picker-containsIntersections())
{
………
}
I picked first point in 3D data and similarly the second point. The primitive
is set for these two points as LINES and a line gets drawn on screen.
osg::ref_ptrosg::Vec3Array points = new osg::Vec3Array;
osg::ref_ptrosg::Vec4Array color = new osg::Vec4Array;
osg::ref_ptrGeometry geometry( new osg::Geometry);
points-push_back(..get first x,y,z using osgUtil::PolytopeIntersector()…);
points-push_back(..get second x,y,z using osgUtil::PolytopeIntersector()…);
color-push_back(osg::Vec4(1.0,0.0,0.0,1.0));
geometry -setVertexArray(points.get());
geometry -setColorArray(color.get());
geometry -setColorBinding(osg::Geometry::BIND_OVERALL);
geometry -addPrimitiveSet(new osg::DrawArrays(GL_LINES,0, points-size()));
I cannot use polytope in the area where there are no data points.
I think my line drawing procedure is wrong and this is why I am not able to do
so in those areas where there are no points.
A line can be anywhere, not necessarily through points, in this space for some
applications.
Thank you!
Cheers,
Lalit
--
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=44722#44722
___
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Draw line in 3D screen
Hi Lalit, I suspect you haven't got any replies because it's impossible to work out what you are actually wanting to achieve with drawing your line - you need to provide constraints on where you'd want to place the vertices of the line, unless you tell us what these constraints might be, we can't provide any guidance to you. Robert. On 2 December 2011 14:41, Lalit Manchwari manchwari.la...@gmail.com wrote: Hi, I am loading a large number of 3D points (X, Y, Z) on OSG. I want to draw line on screen not necessarily passing through loaded points. I am using osgUtil::PolytopeIntersector but it draws lines which essentially pass through loaded points. What can be done to draw line by movement of mouse dynamically anywhere in screen, i.e. could have its nodes on the loaded points and as well on the area where there are no loaded points. Thank you! Cheers, Lalit -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=44191#44191 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Draw line in 3D screen
Hi, a simple line drawing code is below but i'm sure you want more complicated solition. Below you can update the start and end points on the fly by osgGA mouse movement. Code: osg::Vec3 sp(0,-180,120); osg::Vec3 ep(0,480,120); osg::ref_ptrGeometry beam( new osg::Geometry); osg::ref_ptrosg::Vec3Array points = new osg::Vec3Array; points-push_back(sp); points-push_back(ep); osg::ref_ptrosg::Vec4Array color = new osg::Vec4Array; color-push_back(osg::Vec4(1.0,0.0,0.0,1.0)); beam-setVertexArray(points.get()); beam-setColorArray(color.get()); beam-setColorBinding(osg::Geometry::BIND_PER_PRIMITIVE); beam-addPrimitiveSet(new osg::DrawArrays(GL_LINES,0,2)); Thank you! Cheers, Tolga -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=44430#44430 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] Draw line in 3D screen
Hi, I am loading a large number of 3D points (X, Y, Z) on OSG. I want to draw line on screen not necessarily passing through loaded points. I am using osgUtil::PolytopeIntersector but it draws lines which essentially pass through loaded points. What can be done to draw line by movement of mouse dynamically anywhere in screen, i.e. could have its nodes on the loaded points and as well on the area where there are no loaded points. Thank you! Cheers, Lalit -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=44191#44191 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
