topic Re: draw an arc between two points. in .NET Forum

draw an arc between two points.

Anonymous — Mon, 21 Jun 2021 09:41:28 GMT

Hello Guys ,

I am developing a function which will draw an arc of a circle between each of my points, one after the other.
I managed to recover my two points.

But I don't know how to draw an arc between my two points.

for the angle of the arc of a circle:

if the distance between the two points is large, the angle of the arc of a circle is small.

Re: draw an arc between two points.

R.Gerritsen4967 — Mon, 21 Jun 2021 15:08:28 GMT

I think you need more information than just 2 points to draw an arc or a circle.

So you will need something to calculate the start/end angle or arc length or the directions in the start- or endpoint.

Maybe have a look at this link:

https://www.theswamp.org/index.php?topic=40382.0

Look at the post from Gile, this is a very simple way to draw an arc with only 3 points.

Re: draw an arc between two points.

norman.yuan — Mon, 21 Jun 2021 21:29:33 GMT

I assume that you do know given 2 points, there could be infinite numbers of arc to be drawn. So, are you saying you just want to draw arc that pass through the 2 points with a random radius? It sounds not making any sense to me. You may want to explain more on what you need, a picture may help make things easier to explain for you and understand for others.

Re: draw an arc between two points.

Anonymous — Tue, 22 Jun 2021 08:27:07 GMT

Hello guys 🙂

Excuse me if i'm not clear 😞

What i want is to draw an ARC from the first point(3dpoint) to the second point(3dpoint),if the angle can be chosen at random, that's fine with me.

Now

I show you my code a little. but I managed to do this with a Spline.

// Define the fit points for the spline Point3dCollection TroisPoints = new Point3dCollection(); TroisPoints.Add(A); TroisPoints.Add(C); TroisPoints.Add(B); // Get a 3D vector from the point (0.5,0.5,0) Vector3d vecTan = new Point3d(200,200, 0).GetAsVector(); Vector3d vecTan1 = new Point3d(0, 100, 0).GetAsVector(); // Create a spline through (0, 0, 0), (5, 5, 0), and (10, 0, 0) with a // start and end tangency of (0.5, 0.5, 0.0) Spline acSpline = new Spline(TroisPoints, vecTan, vecTan, 1, 0.5); acSpline.SetDatabaseDefaults(); // Add the new object to the block table record and the transaction acBlkTblRec.AppendEntity(acSpline); tr.AddNewlyCreatedDBObject(acSpline, true);*/ } // Save the new line to the database tr.Commit();

But i want to do this whith the ARC .

THANKS A LOT GUYS 🙂