Friday 2010-11-19 Dev. update and Discussion

[winny]

Love the screens.

Can't believe the spiraling tracers is still even under debate. It's a fact.

Lots of things contribute, wing vibration, airflow across the guns, uneven burning of the tracer round, G-force, barrel condition and barrel rifling all contribute to this effect. Most bullets used at the time were also tail heavy (so they tumble easier) which can exagerate the wobble.

[philip.ed]

Thanks, all, for the input on the tracers. Lots of helpful knowledge shared here.
Winny, I wasn't sure on the issue mate. I've had many people swear against the spiralling tracers, stating that the effect is down to the camera shake in gun-cam videos. As has been shown, a lot of evidence suggests that this might have added to the effect, but the effect is definately there

To be Devil's advocate, how large can the spiral get? I'd imagine it's a lot smaller for the .303's and gun-cam videos that I've seen would support this.

Thanks in-advance.
I love the contrails too, they look great.

Oleg, are all effects shown 3D?

[winny]

Originally Posted by philip.ed

Thanks, all, for the input on the tracers. Lots of helpful knowledge shared here.
Winny, I wasn't sure on the issue mate. I've had many people swear against the spiralling tracers, stating that the effect is down to the camera shake in gun-cam videos. As has been shown, a lot of evidence suggests that this might have added to the effect, but the effect is definately there

To be Devil's advocate, how large can the spiral get? I'd imagine it's a lot smaller for the .303's and gun-cam videos that I've seen would support this.

Spiral size is dependant on the size of the projectile. Because they travel nose first they can only spiral by a few degrees off centre before they nose would drop too far and the bullet would start to tumble (nose over tail). The zig-zag effect you sometimes see is due to camera shake but as your video shows, no ammount of shaking camera can recreate a spiral smoke trail.

[kristorf]

'Kin ell, I will need a seperate keyboard just for the commands.............

Many thanks gents

[kendo65]

I'm 99% certain that the spiralling effect in the tracer smoke is down to rifling of the barrel causing the rounds to spin, rather than any camera-shake effect.

I'm really happy that this effect is modelled (visible on many gun-camera films from this era), but as Oleg has said previously all different types of round are modelled - previous tracers showed simple light-streaks with no smoke. I have no doubt that all are modelled accurately.

I'm a little bit surprised at some of the reactions to the spiral tracer smoke though - when the previous tracers were shown there was a chorus of voices asking where was the smoke?!?

[SlipBall]

Yes, the spiralling effect in the tracer smoke is because of the rifling of the barrel...absolutely

[philip.ed]

Once again, thankyou everyone Saves Oleg some time answering, too.

[Richie]

I really like the little JG 26 Crow. One of my favorite insignias. So whimsical.

[Richie]

I think he's funny

[Sutts]

Originally Posted by SlipBall

Yes, the spiralling effect in the tracer smoke is because of the rifling of the barrel...absolutely

I'm sure other factors were at play too as others have recently mentioned. The rifling of the barrel spins the bullet but it takes other factors to exagerate that spin and make it gyrate to the extent we're seeing in the films.