Gizmos seem slow to draw

[franklinblanco]

Hi, I'm trying to draw gizmos for a laser, and it seems to be slow at drawing the actual line. Can't figure it out, already tried to run it on a FixedUpdate of 240hz and 100hz and 60hz, nothing has solved it.

Preview:

Untitled.mov

[franklinblanco]

Additional Context:

Registering the system:

app.add_systems(FixedUpdate, draw_debug_bore_laser)
        .insert_resource(Time::<Fixed>::from_hz(240.0))

System:

pub fn draw_debug_bore_laser(
    query: Query<&GlobalTransform, (With<InPlayerHandsMarker>, With<FiringPoint>)>,
    mut gizmos: Gizmos,
) {
    for transform in query.iter() {
        let max_toi = transform.forward() * 20.0;
        gizmos.line(
            transform.translation(),
            transform.translation() + max_toi,
            Color::Rgba { red: 2.5, green: 0.0, blue: 0.0, alpha: 1.0 },
        );
    }
}

[Ihazevich]

I had a similar issue and I solved it by making sure that the gizmos are drawn after the camera is moved.

[franklinblanco]

Hi, thanks for the reply. In my case the camera doesn't move, it does rotate though.

[ikbencasdoei]

Its most likely because you added the draw_debug_bore_laser system to the FixedUpdate schedule which doesn't always run before the screen is rendered. I would suggest adding it to the normal Update schedule.

[franklinblanco]

Thanks for writing, I initially tried the Update schedule and that's why I tried switching to the FixedUpdate. Now it's on the Update schedule and it still runs like that.

[ikbencasdoei]

Okay because in my experience the gizmos draw instantly, so there are only a few other things I can think of:

• The draw_debug_bore_laser runs before the system that updates the position/rotation, which causes a one frame delay.
  You could fix this using:

app.add_systems(Update, draw_debug_bore_laser.after(/*insert FiringPoint rotation system or label*/))

Or,

• There is somewhere a delay updating the globaltransform.

[suptimal]

@franklinblanco after moving the system to PostUpdate this issue was fixed for me.

app.add_systems(PostUpdate, draw_debug_bore_laser)