Coding an arc-shaped Curve3D (can't calculate "in" and "out" points position)

Glebastik

Hello there! Trying to build an arc-shaped Curve3D with certain length and radius but having difficulties with "in" and "out" points. Can't calculate their position to shape the Curve3D of a circle segment.

The position of the first point is selected by user in 3D world - there is no problem. The second point is placed at the same coordinates, then moved local along X axis by "radius" (center of circle), rotated local by "length divided by radius" radians around Y axis and then moved local along X axis by "- radius". Maybe not the best way, but it works... hope... I can't be sure of this because I can't calculate the position of "in" and "out" points position to get the shape of a circle segment. Lack of mathematical knowledge :# I use CSGPolygon with MODE_PATH and PATH_ROTATION_PATH_FOLLOW and several cubes to visualize the curve and points in 3D world. But the result looks really sad

So I ask for help with these control points.

Saitodepaula

Do you want to draw a perfect arc (segment of circle) or a something like a bezier curve, with nodes/points for manipulation?

If arc, search for something like "draw arc formula", or, if your arc will always be half of a circle, maybe just import a mesh from blender that is half of a circle... an let the user manipulate it by changing the x, y or z scales.

If it's a bezier curve, use the path node from Godot, and expose the path points so that the user can manipulate them.