#Projectile Angle Calculation

1 messages · Page 1 of 1 (latest)

rustic scaffold
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Idk what the code Null gave do, but I can help you write one

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And yes first calculate the time

late karma
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Thanks

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But time in air x and y need t in the equation

rustic scaffold
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But actually watching the video time is going to be removed out

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You can just get the equation from end of the video

late karma
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Is it this?

unknown.png
rustic scaffold
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theta = 0.5f * asin((gravity * distance) / pow(initial_vel, 2));

rustic scaffold
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g is gravity and v0 is initial velocity

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Btw this assumes that start Y and destination Y is the same

late karma
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Is this right?

float g = Vector3.Distance(Physics.gravity, Vector3.zero);
float theta = .5f * Mathf.Asin((g * range) / Mathf.Pow(exitVelocity, 2) * Mathf.Deg2Rad );
late karma
rustic scaffold
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Same thing but still lol

rustic scaffold
late karma
rustic scaffold
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You need to do it later

late karma
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Later?

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So thats not the whole calculation?

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Hello?

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I think it works now, but I'm not sure

rustic scaffold
rustic scaffold
rustic scaffold
late karma
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void CalculateLift()
{
    float g = -Physics.gravity.y;
    float theta = .5f * Mathf.Asin((g * range) / Mathf.Pow(exitVelocity, 2));
    lift = theta * Mathf.Rad2Deg;
}

Does this seem right?

rustic scaffold
late karma
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I placed a target 500m away at the same height as gun and it was a bullseye!
Even when switching ammo types

rustic scaffold
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Nice, just make sure the value in Asin is -1 ~ 1 range

late karma
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It's around 0.01 - 0.001 or something

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Depends on the range

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THETA: 0.001471501
RANGE: 150
rustic scaffold
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Anyways if it works well it's good lol

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I guess your velocity is pretty fast

late karma
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Yeah 1000m/s

rustic scaffold
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Oh okay that makes sense... lol

late karma
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haha

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Thank you so much! You have helped my project a ton!

rustic scaffold
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Your tank project I remember 🙂

late karma
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Ohh, you remember!

rustic scaffold
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Yup I'd bet it's evolving well

late karma
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Still doing the basics, but there are so many new features.

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If you would like to help just a tiny bit more. Could you help me with calculating momentum?

rustic scaffold
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What momentum are you calculating?

late karma
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linear momentum?

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¯_(ツ)_/¯

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I want to calculate when a tank is in neutral. How much does it move forwards based on it's velocity.

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Could be as simple as velocity - drag I guess

rustic scaffold
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Oh alright so how long does it goes forward if there is no input?

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From current velocity

late karma
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Well, okay when the vehicle changes gears the maximum velocity is calculated by the gear ratio.
So that the tank would not slowdown to literally zero when the gear is neutral I would like to get the magnitude of new velocity - current velocity and lerp that with drag.

rustic scaffold
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Sure and it's not using rigidbody I guess?

late karma
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It has a rigidbody, but the movement is based on translating the position.

rustic scaffold
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Alright and does it calculate friction with ground etc

late karma
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Could use velocity as well probably should tho

late karma
rustic scaffold
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and you'd calculate this over time is it?

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Not one frame thing?

late karma
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Yep, over multiple frames. I'm not sure which approach would be the best.

rustic scaffold
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But if you want to do with physics material it's gonna be little harder (maybe better to set rigidbody velocity in that case)

late karma
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No, thanks. I haven't touched those yet

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velocity *= (1 - Time.deltaTime * drag);

rustic scaffold
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Basically that's what Unity is doing yes

late karma
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That doesn't work at all for me

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maybe my variables are wrong

rustic scaffold
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What value are you using?

late karma
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.1 km/h drag

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Got my vehicle going at mach 6 somehow 🤣 ✈️

rustic scaffold
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Drag is pretty much of ratio

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In that equation it should be in 0~1 range

late karma
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slopeLoss is the amount you gain or lose going up or down slope

momentum = speed - newVelocity;

drag = drag + slopeLoss;
momentum *= 1 - Time.deltaTime * drag;
speed = momentum;
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This causes the speed to go up to >1456 km/h

rustic scaffold
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How much value is slopeLoss?

late karma
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-1 going up slope and 0.75 going down

Those are maxes btw.
They are calculated between 0-max using a slopeRatio

rustic scaffold
late karma
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speed is the current speed
newVelocity is the new speed transmitted by the gear box

I should probably be called newSpeed.

late karma
rustic scaffold
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// after applying newSpeed
drag = drag - slopeLoss;
speed *= 1 - Time.deltaTime * drag;

What happen if you just do this? Can you log drag and speed?

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Actually higher drag means slower

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So it should be substraction 🤔

late karma
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Thanks you for your time. I have to go now. I'll catch you later on this thread.

rustic scaffold
late karma
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@rustic scaffold
Hello, I am back managed to get the drag working properly, but I'm struggling with slopeLoss

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This is what I have right now!

momentum = speed - newSpeed;
momentum += momentum *  (-SpeedDirection() * slopeLoss);
momentum *= 1 - Time.deltaTime * drag;

speed = newSpeed + momentum;
        
float lSpeed = speed * Time.deltaTime;
        
vehicle.transform.Translate(-forward * (lSpeed / 3.6f), Space.World);
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SpeedDirection is just speed > 0 ? 1 : -1

rustic scaffold
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I think it should be relative to your marching direction, tho