Article	60001516
Type	HowTo
Product	Engine
Version	6
Date Added	10/19/2011
Submitted by	Rolf Wieland
Keywords

Subject

How can I create a 3D-View lengthwise or crosswise to a line

Summary

do you have an example to create a 3D-View lengthwise or crosswise to a line.
It should be a view as created by ....CommandAction.View3D ( "VFront" ) but the direction of the line is not parallel to x- or Y-axis.
Who to do it ??

Solution

You cannot define a plane by two points or by a single line. For this you need 3 points or two line that have a common point (like their start-point). See the code below

        private void Set_View_by_3_Points()
        {
            //or by 2 lines that have a common point (their startpoint) and that define one plane
            vdDocument doc = vdFramedControl1.BaseControl.ActiveDocument; doc.New();

            vdLine linY = new vdLine(); // this line will define the Y axis
            linY.SetUnRegisterDocument(doc); linY.setDocumentDefaults();
            linY.StartPoint = new gPoint(1.1152,2.5053,-2.3408); //pt1
            linY.EndPoint = new gPoint(0.6050,3.3411,-2.5438);  //pt2
            linY.PenColor.FromSystemColor(Color.Green);
            doc.Model.Entities.AddItem(linY);

            vdLine linX = new vdLine();// this line will define the X axis
            linX.SetUnRegisterDocument(doc); linX.setDocumentDefaults();
            linX.StartPoint = new gPoint(1.1152,2.5053,-2.3408); //pt1 : same as linY.StartPoint
            linX.EndPoint = new gPoint(1.8271,2.7833,-2.9858); //pt3
            linX.PenColor.FromSystemColor(Color.Red);
            doc.Model.Entities.AddItem(linX);

            vdCircle cir = new vdCircle(); //is created just to see the plane where these two lines are
            cir.SetUnRegisterDocument(doc); cir.setDocumentDefaults();
            cir.Center = new gPoint(linX.StartPoint);
            cir.Radius = 0.5;
            cir.ExtrusionVector = new Vector(0.4826, 0.4735, 0.7368);
            cir.PenColor.FromSystemColor(Color.Gray);
            doc.Model.Entities.AddItem(cir);

            doc.CommandAction.Zoom("E", 0, 0); // now UCS is PlanWorld, View is XY plane of PlanWorld
            MessageBox.Show("3D lines created");

            doc.World2ViewMatrix.SetFrom(new gPoint(linX.StartPoint), new Vector(linX.StartPoint, linX.EndPoint), new Vector(linY.StartPoint, linY.EndPoint));
            // the call above sets the View to be the plane that LinX and LinY define

            doc.CommandAction.Zoom("E", 0, 0);
            MessageBox.Show("View changed to be the plane that these lines define");

            doc.UCS("View"); // this is not a call that you need, it just sets the UCS to be the same as the View
        }