I know that it has something to do with geometry, and I know it uses the PI number because of the radius, but I don't know the calculation I have to do. I want to know the shape's surface area because I need to change it's vertical size and I know I can do it by getting the surface area square root (correct me if I'm wrong about that). Well any help will be good for me, and I hope it is possible to calculate. It seems totally calculable though.

Godot version 3.5.1
in Engine

+1 vote

A capsule is really just a rectangle with a 1/2 circle on either end. So, as far as calculating the area, it'd simply be:

• The area of the rectangle (width x height)
• The area of a full circle with a diameter matching the width of the rectangle

In Godot's definition of a `CapsuleShape2D` you define both a `radius` and a `height` value. The `radius` is the radius of the 1/2 circle on each end. The `height` is the height of the rectangle between the 2, 1/2 circles. So, a `CapsuleShape2D` with a height of 0 is essentially just a circle (with a zero height rectangle between the 2 halves).

So, for a real example, let's say we have a `CapsuleShape2D` defined as follows:

`Radius: 10`
`Height: 20`

So, we have the following primitive shapes

• 1 complete circle with a radius of 10
• 1 rectangle with a width of 20 (radius * 2) and height of 20

From that, just calculate the areas of the 2 shapes.

• For the circle, that'd be `PI * radius squared`, so `314.6`
• For the rectangle, that'd be width x height, so `400`

Add those together to get the area of the capsule -> `714.6`

by (19,268 points)
edited by

Thank you for the help, but I found out that for the capsule shape height follow the vertical size of the thing I was using I just needed to take the thing vertical size and subtract by the double of the capsule shape radius.