How do I create a half circle?

Aspose.3D Product Family
1

I have the scene shown below. It’s a holder for a cookie cutter. How do I add a half circle 3mm thick?

var scene = new Scene();
var box = new Box();

var tr = scene.RootNode.CreateChildNode(box).Transform;
tr.Scale = new Vector3(60, 3.0, 2.9);
tr.Translation = new Vector3(0.0, -27.0, -3.1);

tr = scene.RootNode.CreateChildNode(box).Transform;
tr.Scale = new Vector3(60, 3.0, 2.9);
tr.Translation = new Vector3(0.0, 27.0, -3.1);

tr = scene.RootNode.CreateChildNode(box).Transform;
tr.Scale = new Vector3(60, 3.0, 9.2);
tr.Translation = new Vector3(0.0, -29.6, 0.0);

tr = scene.RootNode.CreateChildNode(box).Transform;
tr.Scale = new Vector3(60, 3.0, 9.2);
tr.Translation = new Vector3(0.0, 29.6, 0.0);

tr = scene.RootNode.CreateChildNode(box).Transform;
tr.Scale = new Vector3(60, 56.2, 3.0);
tr.Translation = new Vector3(0.0, 0, 3.2);
2

@ssides0123

 var halfCircle = new Cylinder();
halfCircle.Height = 3;
halfCircle.RadiusBottom = 20;
halfCircle.RadiusTop = 20;
halfCircle.ThetaLength = Math.PI;//half circle
new Scene(halfCircle).Save("D:\\test.obj");

Try this, use a Cylinder with half theta length will generate a circle with thickness.

3

Thank you so much I was trying NurbsCurve and Shape. Never thought of Cylinder().
But how do I fill it in? I tried GenerateFanCylinder, but that didn’t seem to make any difference. I’m also learning how to rotate it. Not sure what a quaternion is.

var scene = new Scene();
var box = new Box();

var tr = scene.RootNode.CreateChildNode(box).Transform;
tr.Scale = new Vector3(60, 3.0, 2.9);
tr.Translation = new Vector3(0.0, -27.0, -3.1);

tr = scene.RootNode.CreateChildNode(box).Transform;
tr.Scale = new Vector3(60, 3.0, 2.9);
tr.Translation = new Vector3(0.0, 27.0, -3.1);

tr = scene.RootNode.CreateChildNode(box).Transform;
tr.Scale = new Vector3(60, 3.0, 9.2);
tr.Translation = new Vector3(0.0, -29.6, 0.0);

tr = scene.RootNode.CreateChildNode(box).Transform;
tr.Scale = new Vector3(60, 3.0, 9.2);
tr.Translation = new Vector3(0.0, 29.6, 0.0);

tr = scene.RootNode.CreateChildNode(box).Transform;
tr.Scale = new Vector3(60, 56.2, 3.0);
tr.Translation = new Vector3(0.0, 0, 3.2);

var halfCircle = new Cylinder();
halfCircle.Height = 3;
halfCircle.RadiusBottom = 20;
halfCircle.RadiusTop = 20;
halfCircle.ThetaLength = Math.PI;//half circle
halfCircle.GenerateFanCylinder = true;

tr = scene.RootNode.CreateChildNode(halfCircle).Transform;
tr.Translation = new Vector3(0.0, 0.0, 30.0);
// tr.Rotation = new Quaternion(1.0, 1.0, 1.0, 1.0);

scene.Save(_outputPath, FileFormat.STLASCII);

Screenshot 2023-01-05 Half Circle.png (14.6 KB)

4

@ssides0123

We are checking it and will get back to you shortly.

5

You can use Transform.EulerAngles to specify the rotation in euler angles(measured in degree), it’s easier than quaternion to understand:

    //There's a bug in exporting non-triangulated meshes in STL exporter,
    //for work-around, you can manually triangulate the cylinder:
    var halfCircleNode = scene.RootNode.CreateChildNode(PolygonModifier.Triangulate(halfCircle.ToMesh()));

    //It's fixed in 23.2, from 23.2 you can just use
    //var halfCircleNode = scene.RootNode.CreateChildNode(halfCircle);

    halfCircleNode.Transform.EulerAngles = new Vector3(90, 0, 0);// rotate 90deg around x axis