Hi everyone!🧡
I've been working hard to get the trickiest parts of my next animation done. Car physics, street destruction, crowd simulation, and sheath play have been my biggest focus points to solve. I'll take you through a brief overview of them!
Car Physics
I was unsure how to do car physics, but since that kind of thing is a big hero item of this next video, it felt like a good place to start.
The car Jay will be driving with the wheels properly spinning and the tires properly contacting the ground. Then Chance picking it up needed to both crumble it under his strong fingers, the glass should explode, and the chassis should stick to his hand as he lifts it up.
Each of these steps took a bit of figuring out and each have their own unique simulations.
Let me quickly break this down:
I moved the car along the road and rotated the wheels to fit the speed.
I simulated the tires contacting the ground so that they would "stick" to the ground and bulge out slightly at the contact point. This is a minor effect but also fairly quick to do.
I use the rotating tire to create a smoke simulation for when Jay tries to escape! A bit of tire squeal and I think that'll create a pretty fun scene! ^^
At first, I tried to let the simulation itself move the car along with the fingers and I spent a bit too long figuring out how to do that. In the end, I realized I could just animate the car moving perfectly in sync with the hand and add destruction effects afterwards. This proved a LOT more clean and robust.
I crumble the car using an MPM simulation. This is a type of simulation that uses a hundreds of thousands of little points or particles that all stick together with a certain strength to emulate real world materials. I set the strength of that sticking togetherness to be fairly high, as well as increase the plastic deformation that we see in metals. This create pretty good and fast metal deformation that I could then deform the car with.
I fractured the windows and blew them out with an RBD solver, which is a rigid body simulation. This is simply treating each little fragment of the glass as a rigid geometry that can collide with the hand, car, and ground. It's a rather simple solver, but I had a lot to learn with this one.
Hand Print
Adding a hand print in the road when Chance leans down to pick up the car.
This uses MPM to crater the ground (like the metal car body above) but of course with different settings for the type of particles. In this shot, there's actually both tarmac and soil. The soil goes underneath the tarmac to cause it to bulge up around the fingers.
After simulating that, I add little pieces of debris shooting up from the cracks. This just adds an extra layer of detail and impact! It's a small addition but it really helps sell the effect.
I add smoke both from the cracks in the ground and the debris. You might be able to tell that the little debris sources actually drag smoke along with them. It's not perfect but I think it has a nice effect :3
I've made this smoke dissipate quite quickly, because I don't want it obscuring the car!
Crowd Sim
Since I'm doing a larger outdoor scene, I wanted to get some dynamic crowd simulation into the shot! I pulled characters and animations from Mixamo and set up 9 different "Crowd Agents" by combining the characters and animations, so they all have three run, three walk, and three idle animations they can do.
I've done some experimentations with crowd simulation and I think I'm at a good point with it! Here you can see a simple "flee" behavior where each agent in the crowd will run away from the big bad 😅 They're all avoiding each other but they don't really have an idea of the street layout.
I've created a setup that also has them idle and walk around, following the sidewalks and crosswalks (by adding colliders on the streets and buildings). So I'll swap between the two kinds of behavior.
Stomping
A shot I'm really proud of!
There's a lot going on in this shot, as you can probably tell haha. The paw prints are created with MPM, again, just like the ground in the hand print. I'm also using debris and smoke in much the same way as the hand!
In this shot you can get a better view of the soil beneath the tarmac. And I really like the second step on the right when, for a fraction of a second, you can see the soil piling up behind his paw.
The cars are all jumping with simulation, of course, and are using mass and shock dampening, making them bounce when they land. I just think it's hilarious watching the tiny smart car go wheee!
Sheath Shot
This shot is probably the one I was most scared of. I had a picture in my mind about how it would look, but I wasn't sure how it would actually come out when rendered. I'm curious what you think about it.
Sorry that the render changes so drastically mid-animation! I had it rendered out for you, but then I changed some things around the other day. And, of course, I just had to render over my own frames >.<
By the way, what are your thoughts on fur vs no fur?
I'm curious what you think :3 They both have merits. Leave your thoughts in the comments!
Of course, Jay will be in these shots! I've just kept him for last because he's much less of an unknown to me 😅
Thank you for reading and for being here with me! I'm working hard to get this video out and I really hope you'll enjoy it ~ 🧡