I recently started a new project. The full project will be a video to show a composting plant and explain how it works.
I started to fiddle with one of the most complex elements in the animation, a wheel loader which dig and carry around different flavours of garbage. 
I started to model it in SketchUp to get the most accurate possible geometry for the mechanic animation.
For the front part, I mostly used simple native tools alongside FredoCorner to round off some edge here and there.
The back part was modeled by subdivisions and then converted to plain mesh and optimized to low poly.
I organized the hierarchy and the pivots in a meaningful way and exported the model to 3dsMax to animate it..
In 3dsMax I created a rigged setup.. the main rig for the bucket is based on 2 different inverse kinematics chains, one for the main arm and the other for the bucket leverage.
The pistons are simply hold togheter using some "look at" constraint, so that no matter how you move and stretch them, they constantly align themselves with each other.
The whole thing is animated along a spline, which is also animated itself with a series of dummies driving the control points, allowing for multiple paths using a single spline.
Actually there is an hidden mesh which animates along the spline, with a few dummies attached and linked togheter using some more "look at" constraints to properly orient themselves when the vehicle turns left and right.
The actual vehicle parts are linked to those dummies, this was needed because the front part of this beast rotates as a whole and the overall rig behavior is more similar to a train than a "normal car" (I know this may sound a bit confusing, but.. it is what it is).
The wheels and the transmission axle simply have their X rotation parameter wired to the main rig X translation parameter along the spline, so that whenever the veichle moves, everything spins nicely accordingly..
After that all this quite complex rig is set up, the whole thing can be animated keyframing only 3 main parameters: percentage along path, bucket height and bucket tilt (and of course the translation of a couple of spline control points when I need to change the path). Everything else follows accordingly.
In 3dsMax I also quickly blocked out a simple test enviroment using freeform and scatter tools to set up the trash heaps.
For the actual plant model I'll use Sketchup based on cad files coming from the real world project, but for the sake of this test, some quick and dirty playground was good enough to start with.. just to check out the main workflow.
In Max I also created a few colliders for the bucket and the front parts to try some physic simulation of the "dynamic" trash..
I then exported the model to Substance for texturing using a couple of UDIM tiles for the main vehicle and a simple atlas for the wheels and tires. Applyed some decals for the logos and used a few generators and particle brushes to add dirt and damages to the materials.
I then imported everything in Unity3d to render it out using the HD Render Pipeline.
I exported different models in a modular way (3 individual fbx for playground/static trash, dynamic trash and wheel loader) for better control and then assembled everything up again in Unity.
The whole lighting is based on an HDRI skybox (with a layer of volumetric clouds added) and a simple directional light for the sun.
In Unity I also added a lot of decals to improve the appearence of the static scene and animated the lights of the Caterpillar just for the sake of fun.
I also created a dozen of smart Cinemachine cameras with different "follow" and "look at" constraints and a bunch of postprocessing effects such as lens flare, bloom, vignette, chromatic aberration and so on..
I recorded the whole sequence and sent it to Davinci Resolve for final postproduction.
I added some cuts to finetune the overall flow and cleanup some imperfection, added the music and the end titles, a couple of simple transitions, but most of all, I did a bit of color correction and color grading to balance the overall lighting and add a little more of "early morning mood" to the scene.
Here's the finished test sequence.. I hope you enjoy it.
