[OPEN-SOURCE] Machinery Modelling Toolkit

[BoredEngineer]

Hello I have implemented simple hovering component from the epic tutorial.I am trying to achieve switchable movement like from tank to hover tank.So what would be the best approach for movement ? Say How would I switch off the tank movement completely so that all the mmt calculation are stopped.Could it be simply through by changing the tick logic ? For movements through key it could be simply through flag I guess that would decide whether to use hover movement or tank movement.

Basically if you don’t want suspension to still work when your tank is hovering just wait till you have a “lift off” so wheels are not stuck in weird positions and then disable physics update functions, like on suspension and friction. You might need to keep updating wheel position, which is easy to go around by adding one branch in skeletal mesh animation update. I can show you how to do it if you have issue with it.

[Freedom911]

You might need to keep updating wheel position.

Umm Why ?

[BoredEngineer]

Umm Why ?

Because light tank (LightTankTraceWheelsWithAnimBPPrototype) which contains all latest features, uses skeletal mesh for animation on wheels and suspension. By default, skeletal meshes lag behind simulating parent by 1-2 frames. To eliminate this issue position of wheel bones is updated manually in BP using chain of these functions:
Event MMT Post-Physics Tick -> Update Anim BP -> Update Animation Wheels (called inside of previous function)
If you are not using skeletal mesh then you shouldn't have this issue.

[Freedom911]

Because light tank (LightTankTraceWheelsWithAnimBPPrototype) which contains all latest features, uses skeletal mesh for animation on wheels and suspension. By default, skeletal meshes lag behind simulating parent by 1-2 frames. To eliminate this issue position of wheel bones is updated manually in BP using chain of these functions:
Event MMT Post-Physics Tick -> Update Anim BP -> Update Animation Wheels (called inside of previous function)
If you are not using skeletal mesh then you shouldn't have this issue.

Thanks for taking the time.Now I get it why I need to update wheel position after I saw the result myself xD

[BringTheSmiles]

Hi BoredEngineer!

Big fan of this project and it inspired me to try and create a tracked vehicle setup myself. But I wonder if you can shed some light on how you get so gorgeous looking tracks?

I'm having loads of issues where if I manipulate the track spline because of changes in the terrain the tracks will shift back and forth.
Also if I make all the tracks point towards the track in front of it to animate the rotation of each track, it will flip over halfway. I'm guessing this would be fixed by somehow explicitly setting the up vector towards the centre of the track loop, but I'm not vector math savvy enough to do that. The rotation at spline point seems to break the moment I start editing the spline in game.

And on top of making this work yours also does physics!

[BoredEngineer]

Hi BoredEngineer!

Big fan of this project and it inspired me to try and create a tracked vehicle setup myself. But I wonder if you can shed some light on how you get so gorgeous looking tracks?

I'm having loads of issues where if I manipulate the track spline because of changes in the terrain the tracks will shift back and forth.
Also if I make all the tracks point towards the track in front of it to animate the rotation of each track, it will flip over halfway. I'm guessing this would be fixed by somehow explicitly setting the up vector towards the centre of the track loop, but I'm not vector math savvy enough to do that. The rotation at spline point seems to break the moment I start editing the spline in game.

And on top of making this work yours also does physics!

Need to look at the code, but as far as I remember these are the tricks:

flipping of the spline up vector - get Y vector from the Transform you get at some point on the spline. Check sign of the Y vector, when spline flips, Y will change sign, when this happens just add 180 degree rotation.

You can’t remove movement of the links along the spline, when spline is stretched/contracted, completely. But you can mask it. Like the smaller the links, the less visible mismatch is going to be. The other thing is to shift them progressively further away from the spline start and choose spline start closer to the area where it will be the most visible, like an open sprocket for example. In case of something like an Abrams or Leopard you can “hide” most of the mismatch under the top protection skirt as tracks there are barely visible. The point of ground contact is good place as well, as this is where grass and dirt can hide it.
You can always stretch links too, as spline gets longer just stretch links by some small amount.

The other alternative is a rigged mesh and material with animated texture. That thing will just stretch.

[BoredEngineer]

It might be easier to look at the old BP implementation first, it doesn’t have features like links alignment to the sprocket but it’s easier to understand. As you figure it out it will be easier to implemented fancier version.

[BoredEngineer]

Updated MMT Content and Plugin to 4.19.1 version of UE4.

[Multipainkiller]

Amazing plugin! Thank you for update and your hard work, I am going to try out. Is any update in future plans for Ripsaw?

[BoredEngineer]

Amazing plugin! Thank you for update and your hard work, I am going to try out. Is any update in future plans for Ripsaw?

Yes, I want to remove it completely
It uses old implementation that lacks features of the new system and less performant. People seam to keep using it as it’s the easiest to tweak so far - single class implementation. New implementation is based on various components and lacks tutorial but it all around superior otherwise.

[Multipainkiller]

Oh, it makes me sad a little. I modeled three types of Ripsaw with swappable parts. Testing those in MMT is great and I have a lot of fun! Admittedly, I still can not connect properly the spring suspension and the arms, but the wheels and tracks work great. And honestly I had hope that someone would help me with this here Does this mean I will not be able to build ripsaw with the new MMT in the future? I am interested in hovercraft and in those aeroski that I would like to adapt to snowbikes. What else will be removed from MMT?Thank you for your answer.

[BoredEngineer]

You can build any kind of tracked vehicles, including half-tracks, using new classes. Look at T-26 as an example, it’s called “LightTankTraceWheelsWithAnimBPPrototype“. You can find it in the main level.
There is nothing particularly special about Ripsaw in the level, it uses the same class as M113, just slightly different settings. While T-26 is reworked from the scratch, if you check YouTube videos, featured development is on T-26, not on old system.

[Multipainkiller]

Hehe, It looks like there is hope for me If I understand it well, it means that I should follow the T-26 build instead of M113 if I want to have Ripsaw even in a better manner. That's great! Thank you for enlightenment! I'm going to look at this closer tonight

[Multipainkiller]

I'm sorry for stupid questions I see T-26 is skeletal mesh. In order to build Ripsaw from T-26, I have to make (rig) skeletal mesh (wheels and suspensions)? Or is a way to build this using my existing static parts?

[BoredEngineer]

I'm sorry for stupid questions I see T-26 is skeletal mesh. In order to build Ripsaw from T-26, I have to make (rig) skeletal mesh (wheels and suspensions)? Or is a way to build this using my existing static parts?

You can do it using static meshes. Skeletal mesh is better for performance, as not only math used to rotate/move bones is executed faster but you uses less components (derived from scene components) which have effect on performance too.