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a question about the function "viewcenter()" of oddbviewport
a question about the function "viewcenter()" of oddbviewport
hi, there is a dwg file in attach files. this file has a layout "layout bud2" which has a viewport.
i use the function "viewcenter()" of oddbviewport to get the coordinate of center point(in modelspce) of this viewport. the return result of "viewcenter()" is a odgepoint2d(x=-23.4304,y=-13.6210). but, when i use acad to open this file, the center point(in modelspace) of this viewport is a point(x=-1200050.0, y=-800040). why?
btw, in other dwg files, the phenomena doesn't exit.
attached files
viewport's center point in model space is returned by
oddbviewport::viewtarget() function.
sergey slezkin
quote:
originally posted by sergey slezkin
viewport's center point in model space is returned by
oddbviewport::viewtarget() function.
hi, sergey, it seems that oddbviewport::viewtarget() didn't always return viewport's center point in model space. there is another dwg file "tt.dwg" in attach files. when i use oddbviewport::viewtarget() to return viewport's center point, it return a point that x=0,y=0,z=0. but in fact, the center point's coordinates isn't equal to x=0, y=0, z=0.
attached files (156.9 kb, 11 views)

sorry, both viewtarget() and viewcenter() should be used to calculate ms center of ps viewport.
viewtarget() returns 3d point - camera target in ms
viewcenter() retuns 2d point in eye coordinates (in viewport plane).
in general case view direction and viewport twist angle should be used too. like this:
code:
oddbviewportptr pvp;
odgepoint3d camtarget = pvp->viewtarget();
odgevector3d viewdir = pvp->viewdirection();
odgematrix3d xform = odgematrix3d:lanetoworld(viewdir) *
odgematrix3d::rotation(pvp->twistangle(), odgevector3d::kzaxis);
odgevector3d xvec = xform.getcsxaxis();
odgevector3d yvec = xform.getcsyaxis();
odgepoint2d center = pvp->viewcenter();
odgevector3d wcntr = camtarget + viewdir + xvec * center.x + yvec * center.y;
sergey slezkin
hi sergey
can you kindly explain me elaborately about your reply..
i have the following questions..
1. viewtarget - camera target in ms space. i have not got this point. by camera target you are going to mean the position of the camera or the position of the point where the camera should look at.
2. at last you calculated a point wcntr. what information this point is supposed to hold. also give me a physical defination of the formulae you are using....
i have not understand your code. please write in an algorithimic way if possible.
with regards
anirban