Scratch

bobbybee · 2012-02-20 07:31:29

I'm working on some physics for a rocket projectile. The rocket can launch and move appropriately, however, I am having trouble getting the required trigonometry for direction. I am currently getting the difference between the last x/y and the new x/y, and then using the atan function with division, but the angle gets messed up when the slopes change.

roijac · 2012-02-20 07:34:44

script, bro

bobbybee · 2012-02-20 07:48:01

bobbybee · 2012-02-20 10:49:49

bump.

Greenatic · 2012-02-20 11:12:53

Perhaps this project by Paddle2See might help? hmm

bobbybee · 2012-02-20 15:24:52

Yeah, but I'm trying to do the physics, not just random trig.

nXIII · 2012-02-20 19:06:45

I see two problems: (1) t does not change at the same rate as x, so you're stretching the function vertically; (2) you should use the atan2 function to map x, y -> θ, rather than just the atan function.

bobbybee · 2012-02-20 19:21:22

How do you implement atan2 in Scratch?

nXIII · 2012-02-20 19:26:02

bobbybee wrote:
How do you implement atan2 in Scratch?

http://en.wikipedia.org/wiki/Atan2#Definition

what-the · 2012-02-20 20:09:36

You want the rocket to point towards the next xy location?
You might want to look at a script I made which does that.
http://scratch.mit.edu/projects/what-the/1178312

It should be possible to make the script even smaller.

Last edited by what-the (2012-02-20 20:13:45)

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#1 2012-02-20 07:31:29

Projectile Angle

#2 2012-02-20 07:34:44

Re: Projectile Angle

#3 2012-02-20 07:48:01

Re: Projectile Angle

#4 2012-02-20 10:49:49

Re: Projectile Angle

#5 2012-02-20 11:12:53

Re: Projectile Angle

#6 2012-02-20 15:24:52

Re: Projectile Angle

#7 2012-02-20 19:06:45

Re: Projectile Angle

#8 2012-02-20 19:21:22

Re: Projectile Angle

#9 2012-02-20 19:26:02

Re: Projectile Angle

bobbybee wrote:

#10 2012-02-20 20:09:36

Re: Projectile Angle

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