14 replies to this topic

[culverin]

I'm a bit confused.
I wasn't here for the closed beta and I have recently started playing.
I have heard there was a jump jet nerf at 1 point.

Jump jets to me right now do feel very physics based.
Something about the thrust just doesn't feel right to me.
Jump jets don't feel like they operate on "X-amount of acceleration" over the course of their fuel tank.




Does anybody remember scorched earth?
I think the parabolic arcs used in this felt in line with my grade 11 physics lessons.
That should look like this.






Am I crazy?

[Mechteric]

There could be other factors here, such as wind resistance. A large mech moving forward is going to displace a lot more "space" than an artillery shell that is made to be aerodynamic. I would guess this would lead to a parabola with a non-equal X component after its reached the apex (a.k.a. stopped thrusting with the jets)

Edited by CapperDeluxe, 02 October 2013 - 09:16 AM.

[General Taskeen]

wind and realism or "resistance" doesn't apply to Battle Tech jumpjets, they jump a certain distance (because space magic), and pretty far at that, but not in MWO

they worked better in other Mech games though

[Khobai]

Other mech games had more realistic physics, thats why.

The problem with MWO is when you jump, your engine throttles down to 0, which kills all of your horizontal speed. And then when you land your engine has to throttle back up and your mech has to reaccelerate. That makes absolutely no sense because your mech should be carried through the air by its forward momentum...

With proper physics, after jumping, your mech would continue moving forward at the same speed it was running, with the only opposing force being air resistance. Air resistance would gradually bleed away your speed, but it wouldnt be an instant dropoff like it is in MWO.

Edited by Khobai, 02 October 2013 - 10:00 AM.

[Mechteric]

Khobai, on 02 October 2013 - 09:39 AM, said:

The problem with MWO is when you jump, your engine throttles down to 0, which kills all of your horizontal speed. And then when you land your engine has to throttle back up and your mech has to reaccelerate. That makes absolutely no sense because your mech should have forward momentum...

not true, ever tried running in a jenner, then doing a 180 degree jump turn while continuing to move in the original direction and shoot at the mech directly behind you. The problem though is that when you're in heavier mechs you get such slow jumping it feels like you're not getting the kind of horizontal motion you feel you should.

Edited by CapperDeluxe, 02 October 2013 - 09:56 AM.

[Khobai]

Quote

not true, ever tried running in a jenner, then doing a 180 degree jump turn while continuing to move in the original direction and shoot at the mech directly behind you.

Yeah and it slows you down to like ~60kph when you should keep going close to 151kph.

Itd be like if an olympic long jumper ran 20mph, then as soon as he jumped, he slowed down to 8mph for no apparent reason. Thats whats going on in MWO.

Edited by Khobai, 02 October 2013 - 10:03 AM.

[Artgathan]

Khobai, on 02 October 2013 - 09:39 AM, said:

The problem with MWO is when you jump, your engine throttles down to 0, which kills all of your horizontal speed. And then when you land your engine has to throttle back up and your mech has to reaccelerate. That makes absolutely no sense because your mech should be carried through the air by its forward momentum...

With proper physics, after jumping, your mech would continue moving forward at the same speed it was running, with the only opposing force being air resistance. Air resistance would gradual bleed away your speed, but it wouldnt be an instant dropoff like it is in MWO.

Both of these are incorrect.

You carry forward at the speed you were moving when you left the ground (when firing jump jets). Additionally there is some finesse in landing - you can make a smooth transition from jumping to running, without that "bump" where mechs freeze for a moment.

Intelligent pilots will also zero their throttle while in the air to benefit from increased heat dissipation.

Mad skills, yo.

[Khobai]

Quote

You carry forward at the speed you were moving when you left the ground (when firing jump jets)

no you dont. your forward speed drops off very rapidly. you can see your speed bleed off. And when you hit the ground your mech physically has to reaccelerate back upto full speed (even if you cushion your landing with jumpjets).

In fact you can prove it with a simple experiment. Have your friend race alongside you in a jenner that goes the same max speed as you. Then jump into the air and watch him race ahead of you while your speed bleeds off rapidly. If you continued going the same speed forward while jumping, then the other jenner would not race out ahead of you. So theres certainly some speed loss midair.

MWO does not use anything close to real physics lol

Edited by Khobai, 02 October 2013 - 10:47 AM.

[Artgathan]

Khobai, on 02 October 2013 - 10:05 AM, said:

no you dont. your forward speed drops off very rapidly. you can see your speed bleed off. And when you hit the ground your mech physically has to reaccelerate back upto full speed.

While you're in the air you're not decelerating. It is only when you hit the ground you actually slow down. Sure, your speed bar is dropping when you're in flight, but you don't actually slow until you touch down. Ever notice how lights manage to "skate" up unclimable hills? The only time you'll slow down in flight is if you clip a corner (a mech, a building...).

[William Mountbank]

No, you're wrong, absolute speed drops off rapidly while in the air. Try jumping at full ground speed in a Spider with max JJs, you will be travelling at maybe 30kph on recontact, down from 151kph. There is then an additional drop on touchdown, as you take leg damage.

[Khobai]

Regardless of the technicalities, its clear theres a problem with momentum, because when you land you should be going close to the same speed you were when you took off.

[Alistair Winter]

Are you saying there's an aspect of MWO physics that isn't realistic?

Spoiler

[culverin]

Hmmmmmm....

The more I think about this, the more it makes sense.




I would presume the easiest way to do this is to remember gravity is -9.8m/s^2 acceleration.
You should be burning jump jets 50% to get your jump, and 50% for a perfectly soft landing.


Jump jets should take some skill to use I think.
Is leg damage in MWO currently velocity based?

How much dmg is done right now on a drop?

[Xyroc]

Its because they set it to where the initial 1.5 seconds ( I believe it is ) delivers more thrust than the rest of the fuel duration.

[Shlkt]

My experience with JJ is that the majority of your thrust time (i.e. the latter part) applies just enough upward force to counter the weight of your 'Mech. So after your initial upward acceleration, the latter stages of JJ fuel consumption only allow you to maintain the upward velocity you currently have.

If you turn off JJs and start to fall, turning them back on again basically prevents your fall from accelerating but it doesn't really slow you down. Your experience may be slightly different in smaller mechs with large numbers of jets, but that's basically how the system feels to me.

Horizontal momentum appears to be preserved 100% on liftoff but there's variable deceleration on landing depending on how hard you hit the ground. Since JJs don't allow you to accelerate upwards after your initial liftoff it's very difficult to land perfectly.

The softest landing possible is generally achieved by turning off your JJs and then flipping them back on as soon as your vertical velocity goes negative. The trick is to have enough fuel remaining to float all the way back to the ground; if your initial launch is too long then you'll run out of fuel prematurely on landing.

Edited by Shlkt, 07 April 2014 - 09:05 AM.