Regular scale points of a circle, but keeping direction, part 2: the normals

Question

Months ago I had a problem and fortunately, MvG was able to help me: Scale position points in a circle.Look like normal scaling

Now I have an additional problem to that problem. I would like to keep scaling the circle points in their normal direction (like the image shows) to fit the more common scaling of a circle (which changes their direction), but I'm missing one thing, the normals, emulated for concept purposes in red.

I'm guessing I could just do a similar parallel calculation with a slightly rotated input and do a cross product.

I was just wondering if someone has a great formula, like before :)

Thank you again.

Answer 1

So, using the way I've mention it works. A slight angle offset and do the same calc in parallel. Just a bit computing wasteful.

So instead of applying the other problem formula once, apply it to two points, one slightly rotated from the other and then use the cross product of Y on both. Doesn't translate perfectly to 3D solutions, but it's fine for this 2D one :)

Cheers