As you may know, I've created a floorplan application using your program. One of the problems I ran into was that until the latest version the ruler did not support real-world measurements like meters and feet. This is/was a symptom of the fact that your program is not really intended for drawing real-world objects, which is fair enough since you're not advertising it as a CAD program.

Now I'm hoping to (mis)use your program even more. I intend to add a building planner view to my floorplan program, which should show a wireframe-like view of a building with composite nodes representing the floors. This should be viewed using the DiagramView3D viewer, with the camera typically looking at the building from about 30 degrees above the ground and 45 degrees from straight-on, i.e., looking at a corner of the building.

As far as I can determine, DiagramView3D does not render the nodes according to the angle of the camera. The size of the node is adjusted according to camera distance, but nothing else - all the nodes are shown as face-on, irrespective of the camera angle. This is not usable for nodes that represent real-world objects - they should be rendered tilted according to the camera angle.

What to do? Is there some way to make DiagramView3D render nodes according to camera angle? Is there some way that I can change the rendering of the nodes to take the camera angle into account?

Thanks.

Thanks for your reply. I'll see what I can do with using four DiagramLink items to represent a floor in the building.

You will have to use connected links with small nodes representing the mesh vertices (make them transparent / invisible if you don't want them to be shown). That's necessary because links don't store any 3D location information but are only drawn as straight lines connecting the projected 3D locations of their Origin and Destination nodes.

The 2D coordinates for each end mean nothing to the 3D viewer, and obviously a single LayoutTraits[View3D.Position] won't let you specify 3D positions for both ends. Its current implementation relies on actual nodes positions, so you cannot avoid them at this time.

PS. Just in case you do consider making some improvements in this area, then I'd prioritize the option of rendering node objects according to camera angle even higher than including unconnected links in the 3D view.

What you could do is to draw projected lines yourself from the view3D.Paint event handler with the help of PointToClient(Point3D) method:

private void diagramView3D_Paint(object sender, PaintEventArgs e)
{
	var cube = new[]
	{
		new Point3D(00, 00, 00),
		new Point3D(10, 00, 00),
		new Point3D(10, 00, 10),
		new Point3D(00, 00, 10),
		new Point3D(00, 10, 00),
		new Point3D(10, 10, 00),
		new Point3D(10, 10, 10),
		new Point3D(00, 10, 10)
	};

	for (int i = 0; i < 4; i++)
		DrawEdge(e.Graphics, cube[i], cube[(i + 1) % 4]);
	for (int i = 0; i < 4; i++)
		DrawEdge(e.Graphics, cube[i + 4], cube[(i + 1) % 4 + 4]);
	for (int i = 0; i < 4; i++)
		DrawEdge(e.Graphics, cube[i], cube[i + 4]);
}

private void DrawEdge(Graphics g, Point3D p1, Point3D p2)
{
	var cp1 = diagramView3D.PointToClient(p1);
	var cp2 = diagramView3D.PointToClient(p2);
	g.DrawLine(Pens.Black, cp1, cp2);
} 

You will also need to implement some kind of Z culling - i.e. do not draw a line when any of its points is behind the camera of you will get strange results.

I hope that helps,
Stoyan