Tag: Auto

Designing 3D Volleyball Training Tools on the Fly | January 01 2026, 21:21

What I did on the plane to/from vacation and sometimes in between: 3D visualization and editing volleyball schemes for Nadya (she’s a coach). This court in the attached image freely rotates, players can be placed on it, and the ball and player paths are shown – all in 3D.

The ball’s trajectory is calculated so that it does not cross the net when moving from A to B (Bezier formula). Players can take several poses – right now there are hastily made poses for serve, attack, block, pass/receive. Interestingly, in the code: I had to write a bit of “volleyball brains”. The system itself calculates the ball’s trajectory through Bezier curves so that it always passes over the net. Moreover, the height of the launch depends on the type of action: for an attack, the ball “launches” from a higher point than for a pass. I also added auto-rotation: the 3D model itself turns its face to where, according to the scheme, it needs to pass or run.

The longest and most difficult task was creating the 3D model of a female volleyball player. To generate a realistic volleyball player, I used the tripo3D service. It gave me a model in a neutral pose (for free). Theoretically, you can then use Blender and the Rigify plugin to attach an armature to it and move its arms and legs, which would recalculate the model.

However, in reality, this approach does not work well: the AI-generated model contains a large number of geometric errors, which the renderer forgives but Rigify does not. They can be roughly divided into two types — incorrect polygon normals and issues with non-manifold geometry, which are significantly more challenging to fix. Inside the body, there may be “floating” clusters of polygons or intersecting surfaces. When Rigify tries to calculate weights (which bone affects which part of the skin), this internal noise confuses the algorithm, and as a result, the weights are distributed chaotically (for example, moving the arm might start pulling the mesh on the stomach). Plus, the model is slightly asymmetrical.

Non-manifold is a geometry error where the topology of an object ceases to be correct in terms of a three-dimensional body: edges may belong to more than two polygons, polygons may only touch at vertices or edges without a common volume, and “hanging” surfaces or zero thickness may appear inside the model. Such geometry formally does not describe a closed volume, causing problems with rigging and deformations. Moreover, the model needs to be simplified because millions of polygons are not needed for rendering in real-time in a browser.

I fixed these using MashLab, additionally refining by hand (“with a file”). In the end, the model turns out slightly different from the original almost everywhere. The original model had “skin” in the form of textures – the face, shirt, and shorts had to be colored. How to transfer all this to a simplified model? For that, there’s a special operation in Blender called Baking. This also involves some tricks. In the end, it didn’t transfer perfectly, but perfection isn’t necessary yet.

Next, we attach the armature to the “joints”, and after about three hours of figuring out why everything does not work as it should, it finally worked. I made four poses, and now each circle (player) can be told which pose it is in.

I’ll also need to make dynamic changes to the uniform colors – that shouldn’t be difficult. There’s also an idea to transfer poses from photographs – this is more complicated, but generally feasible. Using MediaPipe/AlphaPose, you can detect key points in 2D, then some models like HMR/HybrIK can “lift” flat coordinates into 3D space, outputting relative joint rotation angles. The resulting data can be attempted to be projected onto a Rigify skeleton. Since the proportions of the generated volleyball player and the person in the photo may not match, that’s exactly why Inverse Kinematics (IK) is used. This part is quite complex, but overall it’s not strictly necessary – just interesting to figure out and make something functional.

Video in the comments

Exploring Aescape: A Robotic Massage Experience | December 19 2025, 21:26

Nadia and I tried out the Aescape robot massage. Well, I was interested to see the technical side of it all. Overall, it’s quite interesting, but driving 45 minutes instead of 15 to get a robot, even if it’s slightly cheaper… not sure it makes sense to go there regularly. It’s a different story if you’re already at the gym and want a massage right now, without an appointment – it’s like a deluxe massage chair. Yes, in that case, it’s exactly what you need.

The system scans the body with four cameras on the ceiling, creates a 3D model, and then on the whole, the robot arms do a pretty good job of kneading the muscles just right, stronger in some places, gentler in others – considering the overall anatomy, and the specific person on the table. Some might wonder, won’t they accidentally maim someone due to some bug, but we drove there and back on Tesla’s autopilot, and if the cars were going to kill us, they’d have had an easier chance.

Living Without Autopilot: A Surprising Reunion with My Tesla’s Upgraded Skills | December 09 2025, 19:30

Lived several months without autopilot in the car, now I turned it on, and during this time the car has learned not only to drive to a location across the city and through backroads, but also to find parking at the destination and park itself. But when I told it to come home, specifically pointing it to where it gets fed (charger), it stopped in front of the neighbor’s house. Makes you think;) but overall, very cool, Tesla

Alien Encounter and Parking Woes: A Bizarre Day | December 07 2025, 01:21

Such a “facehugger” jumped out of an egg nearby and attached itself to the windshield of my RAV4, just like that to implant its embryo, but the little car held its ground.

It all started when I went outside with my keys and realized that the car was not in the yard. Damn! I had used it to get to the metro, and Nadia brought me back from the concert in Washington in her Tesla. Well, okay, I’ll call an Uber.

The Uber took me to the metro parking lot, where the local parking attendants had found my car overnight and slapped a yellow card on it. Removing this thing takes five minutes; you just need to pay the fine by scanning the QR code. Luckily, the fine was divine, just 75 dollars accumulated. If I had remembered later, it would have been more.

Smart Car Seat Selection: How My Tesla Knows the Driver | November 03 2025, 14:29

Incidentally, in my Tesla, there’s a very clever system for identifying the driver. If I enter the car first but sit in the passenger seat, placing my phone immediately in the central console for charging, and then Nadia enters second but sits in the driver’s seat and also places her phone there, her profile is selected automatically because she’s the driver, even though both phones are on charge under the central console.

So, there are two possibilities: either there is an antenna which can precisely detect that a phone has crossed the driver’s door rather than entering the car in any other way, or there is a camera focused on the driver. In any case, it’s very reassuring that it “just works”.

From Tesla Model Y to Model S Plaid: A Swap Experience | October 14 2025, 16:51

Recently, my Tesla Model Y fell ill, and the dealership gave me a Model S Plaid as a loaner car. It’s simply a monster, accelerating to 100 km/h in 2 seconds. Over a thousand horsepower. But after driving it for a week, Nadezhda and I realized that we would still not trade our Model Y for a Model S.

Well, the fact that it’s unusually low to the ground is a minor issue. We would get used to that. But getting out from behind the wheel is always incredibly awkward for me. My belly isn’t that big, but in the Model S, it’s like a real cockpit. You have to carefully sit down and climb out, whereas in the Model Y, you just jump in somehow and go.

Moreover, the Model S is really noisy inside compared to the Model Y. You can hear the road. And this is for a price twice that of the Model Y. Also, for some reason, the mode where you just walk away from the car works less sensitively, and locks the car only when you are already quite far away.

And then there are the turn signals. What idiot decided to put their buttons on the steering wheel? It’s impossible to get used to that. The steering wheel still turns, and the buttons are always somewhere unclear.

But, damn it, it’s very beautiful from the outside. Especially with a light interior.

By the way, Tesla has somewhat poorly thought out the mechanism for issuing a replacement car, and it works with only one driver. You can’t set two keys for two different phones. Moreover, it would be nice to store the settings in the cloud and receive a replacement car already adjusted to your preferences.

And the car fell ill in an interesting way too. It’s funny when the car on the highway tells you that there’s a little problem, the engine is dead, but you should not distract yourself, just keep driving. After parking, the car might theoretically not drive, but so far all is normal. If not, we will tell you. Meanwhile, your drive will not sound the same.

As I understood, the car simply switched from 4-wheel drive to 2-wheel drive. Funny that such a fallback exists at all. Already fixed, it needed an inverter replacement.

The Ingenious Mechanics of Modern Fuel Pumps | September 28 2025, 13:36

With the purchase of a Tesla, there’s sudden interest like a fuel nozzle understanding that the tank is full. And a couple of other interesting findings on the topic.

There used to be an awkward problem at gas stations. Customers didn’t know when their tank was full and gasoline often spilled over. Engineers came up with a genius solution.

Inside the fueling nozzle, there’s a thin tube that pulls air from the car’s tank into a special membrane chamber (if you look at the “nozzle,” there will be two holes) When you press the trigger, fuel flows until the tube is submerged in gasoline (which means a full tank) and the air flow stops.

This creates a vacuum, which pulls three little steel flaps into the center of the mechanism, instantly releasing the trigger and cutting off the fuel supply.

By the way, approaching the diaphragm valve in the channel there is a compartment with a small ball inside. If for some reason the fuel nozzle falls out of the tank, the ball will block the vacuum channel, provoking a sharp increase in vacuum – and triggering the process described above.

It also turned out that the diesel nozzle is larger in size so it cannot be mistakenly inserted into a gasoline tank. But the opposite mistake can happen. Although they could have invented a different design that would work both ways from the start.

When a tanker refills an underground reservoir, the valve automatically closes when the tank is nearly full, and the gasoline vapors are sucked back into the tanker through another hose, where it condenses back into liquid fuel.

And it also turned out that if you drive away with the hose still in your car, there will be no fireballs, spilled fuel, or toppled gas pump. The hose connecting the nozzle to the pump is designed to disconnect into two parts when a certain force is applied. Next time you are at the gas station, pay attention to the metal connector on the hose. That is the break point. When the hose disconnects and you drive away, the area of the hose breaks, built-in valves in the hose cut off the fuel, but, of course, the pump will not operate for some time until everything is put back to normal again. Interestingly, this risk is considered and damage is minimized.

Oh, and here’s something for those who haven’t driven in New Jersey. By law, it’s prohibited to refuel your own vehicle. At all gas stations, there are attendants who do it for you.

Revolutionizing Car Safety: Pre-Collision Airbag Deployment and Smart Updates in Modern Vehicles | September 24 2025, 12:54

So far, I have only one car model and brand that can deploy airbags not at the moment of impact, but a moment earlier, so that by the time of the impact, it’s not too late to do so. We’ll see what the news shows, but tests indicate that this thing works better than the traditional method. Reality might turn out to be harsher, but we’ll keep an eye on it.

It’s also interesting that the car started to receive new exciting features after purchase. I never had this experience before. What you bought it with, you lived with, and sometimes you could go to the dealership for something new, and it usually involved replacing something physical.

The previous update (not very useful to me, but maybe to someone) was about automatic detection of children and animals in the cabin. And if it turns out they were left inside while the owner left, the car does not turn off the climate control. And of course, it screams into the app that this is not a good thing to do.