Algodoo

work · by **Rideg** » Tue Oct 05, 2010 9:45 pm

Hello I'm making a "gun" and I've got the "fire" spawner wich spawns a bullet and launches it towards the target.

Now, the spawner has a laser that's triggering it and it's pointed from the right to the spawner.
How can I make the shells to have a velocity that's pointing down? Consider that the gun is rotatable so the "down" vector isn't always down if you have aimed upwards, it wont be pointed vertically. I'm using the right laser triggering to make the bullets go with a velocity * the normal so I can't use that.

Thank you for taking your time reading this
-Johan

by **Nait** » Wed Oct 06, 2010 5:09 am

As I know

Code: Select all: normal = [cos, sin]

So try to go this way

Code: Select all: math.atan(e.normal(1)/e.normal(0)) // angle math.atan(e.normal(1)/e.normal(0))-1.571 // 1,571 rad = 90 degree // So in the end we have vel:=[math.cos(math.atan(e.normal(1)/e.normal(0))-1.571), math.sin(math.atan(e.normal(1)/e.normal(0))-1.571)]

It works! I have check)
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PS
Instead -1.571 You can place number in radians or formula

Code: Select all: (A/180*Math.Pi) // A - number in degrees

So there is the same as

Code: Select all: vel:=[math.cos(math.atan(e.normal(1)/e.normal(0))-(90/180*Math.Pi)), math.sin(math.atan(e.normal(1)/e.normal(0))-(90/180*Math.Pi))]

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PPS
More correct code is

Code: Select all: vel:=e.normal(0)>0?{[math.cos(math.atan(e.normal(1)/e.normal(0))-1.571), math.sin(math.atan(e.normal(1)/e.normal(0))-1.571)]}:{[math.cos(math.atan(e.normal(1)/e.normal(0))-1.571), math.sin(math.atan(e.normal(1)/e.normal(0))-1.571)]*(-1)}

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PPPS