I would draw a circle on the floor in 3D. I know that an ellipse will be the result. I searched a lot but only found this: http://chrisjones.id.au/Ellipses/ellipse.html and this: https://gamedev.stackexchange.com/questions/188076/how-to-project-a-3d-circle-ellipse-to-2d Luckily I found source code there. The result is this project. Method 1 uses list, method 2 uses local variables. Repeat the method per 1/30 second. Hide/show the ellipse (draw or only compute) Show lines or not (slow). Unfortunately this is a bit slow. In Scratch, only 60-80 ellipses can be displayed in 1/30 second... Well, 1800-2400 ellipses per second, but... I would use it in the 3D TRON project displaying a lot of circles on the grid floor and on the spheres but I could only draw a few considering the speed of Scratch.
