@cvp - that’s a tremendous help, many thanks.
For anyone who might want help with ui and scene path drawing when searching in the future, here’s the complete working code (when using the ‘new’ render loop not the classic render loop):
import ui from scene import * class MyScene (Scene): def setup(self): self.background_color = '#00006b' self.centre = Point(self.size.w/2, self.size.h/2) def update(self): pass def touch_began(self, touch): # Calculate vector between centre point and touched point dx = touch.location.x - self.centre.x dy = touch.location.y - self.centre.y # Draw path from centre point to touched point path = ui.Path() path.line_width = 4.0 path.move_to(-dx,dy) path.line_to(-dx,dy) path.move_to(0,0) path.line_to(dx,-dy) # Create line node from path line = ShapeNode() line.path = path line.position = (self.centre.x, self.centre.y) line.stroke_color = 'white' self.add_child(line) # Place dots at centre and touch points dotA = Dot(location = self.centre) self.add_child(dotA) dotB = Dot(location = touch.location) self.add_child(dotB) class Dot(ShapeNode): def __init__(self, *, location, **kwargs): circle = ui.Path.oval(0,0,20,20) super().__init__(circle, fill_color='white', **kwargs) self.position = (location.x, location.y) run(MyScene())