Need help to find a math equation...

[OneBadPsycho]

Hello, I have searched and searched over the Internet for an equation for a ball hitting a wall and then changes angle... (Thoose i found didnt fit my needs)
Like this:

I would apprieciate if anyone can give me the equation/formula.

Thanks in advance.

 

[Larcenist]

Are you sliding the ball or is it moving by order?

 

[Flare]

Link

I did this for someone else already ^^

In your case, the mirror is the wall

 

[Larcenist]

Ok that was a lot easier than what I had in mid, using the pythagorean theorem to calculate the distance from the wall to the ball's previous location, then from there calculating the angle from the previous point to the wall, multiplying that by 2 and then subtract that from 180 xD.

 

[Flare]

Well, I haven't actually tried out my idea (most of it was just imagining how it would turn out ) but I -think- it will work fine

 

[OneBadPsycho]

@Larcanist
Its sliding.

@Flare
Hmm, it doesn't seem to work properly.

This is my code:

Wall
    Events
        Unit - A unit enters Bound 1 <gen> [B](This region is ontop of the map. I have 4 bounds, 1 in each side, so if the trigger could be made to include all the bounds, it would be nice)[/B]
    Conditions
        ((Entering unit) is in SpellUg) Equal to True
    Actions
        Set OLoc = (Position of (Entering unit))
        Set OAngle = (Facing of (Entering unit))
        Unit - Move (Entering unit) instantly to OLoc, facing (OAngle + (2.00 x (0.00 - OAngle))) degrees
        Custom script:   call RemoveLocation (udg_OLoc)
        Custom script:   set udg_OAngle = 0

The unit just keep moving up and down at the line like periods, until it dies: (The green line)

 

[Flare]

Is Bound 1 at the left side of the map?

also:

Custom script:   set udg_OAngle = 0

Whats the point in doing that? You are giving it a new value everytime the trigger runs anyway

 

[OneBadPsycho]

No, at the very top

 

[Flare]

change the 0 to 270

0 would imply that the wall is facing right i.e. at the left side of the map
90 would be facing up i.e. wall is at bottom
180 would be facing left i.e. wall is at right
270 would be facing down i.e. wall is at top

 

[OneBadPsycho]

270 works at bound 2, which is to the left, but its still moving like periods, could that be caused because of the summoned/slided unit still in or reenters the region?

 

[Flare]

Enters a region doesnt work while the unit is in the region :S

 

[OneBadPsycho]

But i think he actually moves abit further than the region before it change angle... Sec, gonna check it.

Edit: Got it to work, I just increased the region sizes!
Anyway, thanks +rep! :thup:

 

[OneBadPsycho]

It wont work properly...

Flare, the math equation doesn't work properly (I think), could you please take a look at my map?

Thanks in advance!

 

[OneBadPsycho]

-bump Flare?

 

[robinremue]

-bump Flare?

Send em a Private Message

 

[Ninja_sheep]

The angle it goes to and the angle it comes from are always the same.

Spoiler

angle 1 and 2 are always the same. Doesn't matter in wich angle the ball hits the wall.

The only problem is to find the angle of the wall. If you only have walls that go south-north and east-west it shouldn't be too much of a problem.

Hope noone posted that before

 

[Flare]

Hmm, can't seem to fix it :S

When I return the angle at (wall facing - unit facing), the unit goes in the exact opposite direction of the wall, but when I return the angle at 2*(wall facing - unit facing), it goes in the wrong direction :S

 

[tom_mai78101]

Try a negative 1.

 

[Flare]

Tried it

 

[Darthfett]

Lets say the unit is bouncing off the wall at the top or the bottom.

The only difference in the velocity of the unit and angle is that the y velocity is changing to up from down or vice versa.

So what you need to do is split the angle into its x and y values, and make the y value negative:

Since Cos(θ) = X / Velocity
and
Sin(θ) = Y / Velocity

The X = Velocity * Cos(θ) and
The Y = Velocity * Sin(θ)

Making it bounce off of a wall that is above or below the unit would be inverting the Y, and making it bounce off of a wall that is to the left or right of the unit would be inverting the X (negative x/y)

so if you want it to bounce off a top or bottom wall:

Angle = @
X = Velocity * Cos(@)
Y = Velocity * Sin(@)
Set Y = 0 - Y

Now to get the Angle back,
Set @ = Arctan(Y/X)

The only difference for a left or right wall would be setting X = 0 - X instead of Y.

If you post your trigger/code with the sliding, I can help you implement it into your map.