I have a missile actor in my game that uses the projectile movement component. I need it to start off at a slower speed then increase in speed shortly after launch. Despite watching several videos that say to set the Max Speed after you set the inital speed, the projectile does nothing but travel at the initial speed. Max Speed has zero influence on the speed, and seems only related to a homing projectile, which mine is not. I cannot find a way to ramp up the speed after it launches. Should I just use the “Add Impulse” on Tick node using a timeline and get rid of my projectile movement? Would this have less accurate physics than using the PMC? For those interested, I am using this for approximating the speed of an anti-tank rocket weighing 2.6 Kg and needs to achieve a speed of 15,250 cm/s (or unreal units).
- you could Tick / Timeline
Add Force(not impulse) - you could use an actual physics thruster component
Both would interfere with the PMC, though. Could you instead work with effecting PMC’s velocity directly? As in:
This is just a silly example where we add 1% velocity per frame (you could, ofc, add a constant, too). But I believe you’d get most control if you sampled a curve. Or use a Timeline output that adds to velocity.
approximating the speed of an anti-tank rocket weighing 2.6 Kg and needs to achieve a speed of 15,250 cm/s (or unreal units).
Alternatively, if using the PMC is not a must, do have a look at the Physics Controls plugin (experimental). It allows you to set targets the physics engine must achieve. While it’s quite involved, the general idea for this very purpose would be to:
Minor bugs are present but it generally works surprisingly well. You can have many controls affecting the same body instance and modify their targets on the fly, it’s fully run-time. Achieving Target Velocity should be pretty trivial.
Sadly doing what you pictured here did nothing to affect the projectile speed, and I used a rather large number too…what did I do wrong? My projectile just falls straight down. I appreciate your answer though!
Well, yes. You’re multiplying its velocity and the gravity is on, so you multiply what the gravity is doing (I had it off). Generally speaking, the PMC is for non-accelerating projectiles bar the Homing variant. Overriding velocity let’s you keep all the good stuff the PMC offers but you will need to account for other stuff yourself.
If you’re leaning towards simulation, you may need to stick to pure physics. No PMC shortcuts, no Physics Control.
- Add Impulse to Fire (or Set Linear Velocity)
- Add Force every frame (or at least several times per second)
- Add Impulse to Fire (or Set Linear Velocity)
- Add Force every frame (or at least several times per second)
I will mark this as a solution, because that’s what I ended up doing (Pardon my spaghetti, I have other code hooked up to help me see the in-speed flight):
On begin play, I launch it to get the projectile going at 117 m/s, theeeeen…
…I add the needed thrust over 6 seconds to get the projectile up to needed final speed of 294 m/s.
Works pretty good! THANK YOU Everynone for helping me figure this out, in my case for what I needed, this seems to be working great.
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