Robert Garrett
69403bc6ca
The velocity component never got updated. Instead, the system was only calculating the current frame's deltaV. That instantaneous dV and any velocity that *did* get assigned (bundle insertion, keyboard control) would be added to the position. Now forces are integrated into velocity, and velocity is integrated into position. You know... like a real integration function.
24 lines
725 B
Rust
24 lines
725 B
Rust
use bevy::prelude::*;
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#[derive(Component, Default, Deref, DerefMut)]
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pub struct Velocity(pub Vec3);
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#[derive(Component, Default, Deref, DerefMut, PartialEq, Debug)]
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pub struct Force(pub Vec3);
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pub fn apply_velocity(
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mut query: Query<(&mut Transform, &mut Velocity, &mut Force)>,
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time: Res<Time>,
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) {
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for (mut transform, mut velocity, mut force) in &mut query {
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// integrate forces into new velocity (assume mass of 1kg)
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let delta_v = **force * time.delta_secs();
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velocity.0 += delta_v;
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force.0 = Vec3::ZERO; // clear force value
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// integrate velocity into position
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let delta_p = **velocity * time.delta_secs();
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transform.translation += delta_p;
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}
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}
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