Yes for the 1,000,000th time!!
Blitz3D Forums/Blitz3D Programming/Yes for the 1,000,000th time!!
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| I need to make a vehicle move forward with a a keydown command, but I don't want the motion to be a linear movement. I'll like it to accelerate from a stop then decellerate after I release the key. I know I've asked this question before. I just don't remember what the result was. |
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| The best solution in my opinion is to use a physics sim engine like Tokamak or ODE. If you don't want to do that, I can't really help you because I have no experience in the field of car physics... |
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| Keep track of the velocity vector of your entity (using a type.) Each frame, apply a little force in the correct direction if the player is holding down the accelerator. Also, multiply the vector by a drag coefficient to achieve decceleration. |
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You could use Sin() function. Have a counter variable:
speed# = 0
speed_factor# = 2.0
while not keyhit(1)
if keydown(200) then
speed = speed + 0.1
elseif keydown(208) then
speed = speed - 0.1
else
if speed < 0 then
speed = speed + 0.05
if speed >0 then speed = 0
elseif speed > 0 then
speed = speed - 0.05
if speed <0 then speed = 0
end if
end if
MoveEntity car, 0, 0, sin(speed) * speed_factor
updateworld
renderworld
flip
wend
end
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| ok, without giving you the answer it's best to think of it in these terms: you need a few variables 1. the car 2. the amount of thrust when key is pressed 3. the cars velocity 4. the friction coefficient that will slow the car down Friction = .99 if key is down then thrust = 0.01 car_velocity = car_velocity + thrust car_velocity = car_velocity * friction add the car velocity to the car position in b3d you can just rotateentity and moventity. the sin/cos is done for you |
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| The Sin used above, is to give a gradual acceleration and friction :o) |
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| Sweet! That was it. Pretty easy! |
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| http://www.blitzbasic.com/Community/posts.php?topic=47422#527131 |
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| Very nice code Rob! |
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