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chocolat_en_poudre wrote: ↑Mon Oct 23, 2023 1:38 pm Hi ! I just started learning love2d and im making a smash bros like game with bump.lua but it hasn't gravity fonctionality.
Can someone help me how to implement it please ?

darkfrei wrote: ↑Mon Oct 23, 2023 3:13 pm

chocolat_en_poudre wrote: ↑Mon Oct 23, 2023 1:38 pm Hi ! I just started learning love2d and im making a smash bros like game with bump.lua but it hasn't gravity fonctionality.
Can someone help me how to implement it please ?

Just add the vertical acceleration multiple dt to you vertical velocity and than vertical velocity multiple dt to your vertical position.

tourgen wrote: ↑Tue Oct 24, 2023 1:03 am F = m * a. m = mass. a = -9.8m/s^2 at ~ sea level (gravity). -> a = F/m. Given mass of your player, F is solved for.

velocity is the integral of acceleration. If you are not familiar with calculus, calculate velocity incrementally each timestep (using dt) i.e. v = dt * a, where a (accel due to gravity) is negative (see above, -9.8). the negative denotes down. positive is up. The second integral of accel is position, FYI.

vy = vy + dt*g -- positive g to fall down (positive Y direction)
y = y + dt*vy

-- see https://love2d.org/forums/viewtopic.php?p=256873#p256873
y = y + dt*(vy + dt*g/2) -- changing position to half changed velocity
vy = vy + dt*g -- full changed velocity

darkfrei wrote: ↑Tue Oct 24, 2023 8:39 am

tourgen wrote: ↑Tue Oct 24, 2023 1:03 am F = m * a. m = mass. a = -9.8m/s^2 at ~ sea level (gravity). -> a = F/m. Given mass of your player, F is solved for.

velocity is the integral of acceleration. If you are not familiar with calculus, calculate velocity incrementally each timestep (using dt) i.e. v = dt * a, where a (accel due to gravity) is negative (see above, -9.8). the negative denotes down. positive is up. The second integral of accel is position, FYI.

Almost right
But the gravity is an acceleration without a = F/m, this acceleration is absolute same for heavy and light masses, you can skip here any mass using. It's enough:

Code: Select all

vy = vy + dt*g -- positive g to fall down (positive Y direction)
y = y + dt*vy

Of if you want to be more precise:

Code: Select all

-- see https://love2d.org/forums/viewtopic.php?p=256873#p256873
y = y + dt*(vy + dt*g/2) -- changing position to half changed velocity
vy = vy + dt*g -- full changed velocity