- #1

tabris556

- 4

- 0

This is for animations and so the window that an individual sees is based on frames and an FPS that the user can set. The issue that I am seeing is what my graph displays and what I am seeing in code for the values that are being calculated. I will give an example.

Lets say I set up a curve that starts at Frame 0 and goes to Frame 10. At frame one along the curve in my graph I see that the value should be at 0.5, I am just making up these values to show my point. Now when I go into my code and use the cubic bezier equation

B(t) = (1-t)^3*P0 + 3*t(1-t)^2*P1 + 3*t^2*(1-t)*P2 + t^3*P3, I am trying to solve for what B should be at each frame. I assumed I just had to take each frame and convert it from total distance to fit into 0-1. So for frame 1 I am using 0.1. When I plug the value 0.1 in I see a noticeably different value. I have done some testing and see that I get the actual value for Frame 1 when t = approximately 0.1199. This has been bugging me for some time and so I have used several different equations to verify this including the Bezier equation above and De Casteljau's equation to solve at t. I am getting the same answer for everything.

I also know that the graph is drawing correctly because the values at the end points are in the correct location.

My question to everyone is what am I missing and where does that value come from? Thank you to all.