It always seems like a missed opportunity that trackballs don't detect when you twist the ball. It would be so natural for spinning a model in CAD or zooming.
The easiest approach would probably be to add a second optical sensor and do some math to calculate the twist rate.
These have been made on and off since 1995 at the latest. They never work out even though you'd think they'd be super popular for 3d modelers at least. I first encountered one for SGI workstations.
A lot of people who haven't seen one are confuse it with a trackball, but SpaceMouse and its kin aren't trackballs, they're double cascaded joysticks on a fixed mount shaped like a ball.
The stump om the base works as a 2 axis tilting joystick, and the stem of the ball works like its own 2 axis XY sliding pad with extra push/pull plus twist axes. There's a wire through the stem of the knob to get the readings. Together they capture the whole 6 axis deflections for the knob.
Trackballs OTOH is just rubbing a mousepad rolled up to be a ball to operate a Magic Mouse while charging.
Mouse sensors are usually ~16x16 CMOS cameras that just return signed int X/Y movements. Shutter speed is goverened by both luminosity and polling rates. There's no raw pixel output, and even in sensors that have it, it's for focus adjustment only and not useful in realtime sensing. They're also crazy cheap.
Therefore the cheapest way to do ball twist is to just put two sensors and use the error as the twist amount. You could use a singular high resolution highspeed camera pointed at the ball instead, but that won't be the cheapest way to do it.
With only one you can't detect rotation around the axis that goes through the sensor, and for rotation close to that axis the resolution will be very poor.
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It always seems like a missed opportunity that trackballs don't detect when you twist the ball. It would be so natural for spinning a model in CAD or zooming.
The easiest approach would probably be to add a second optical sensor and do some math to calculate the twist rate.
This guy made exactly what you describe
https://youtu.be/u1v7TXViRi8
These have been made on and off since 1995 at the latest. They never work out even though you'd think they'd be super popular for 3d modelers at least. I first encountered one for SGI workstations.
https://en.wikipedia.org/wiki/SpaceOrb_360 as one example.
A lot of people who haven't seen one are confuse it with a trackball, but SpaceMouse and its kin aren't trackballs, they're double cascaded joysticks on a fixed mount shaped like a ball.
The stump om the base works as a 2 axis tilting joystick, and the stem of the ball works like its own 2 axis XY sliding pad with extra push/pull plus twist axes. There's a wire through the stem of the knob to get the readings. Together they capture the whole 6 axis deflections for the knob.
Trackballs OTOH is just rubbing a mousepad rolled up to be a ball to operate a Magic Mouse while charging.
I love the SpaceOrb 360 and still have mine but there are no drivers for it anymore.
Twist scroll requires two sensors and is patented by Kensington.
Is it this one?
https://patents.google.com/patent/US20050184962A1/en
...
Do you know until when?
Why does it require two sensors?
Mouse sensors are usually ~16x16 CMOS cameras that just return signed int X/Y movements. Shutter speed is goverened by both luminosity and polling rates. There's no raw pixel output, and even in sensors that have it, it's for focus adjustment only and not useful in realtime sensing. They're also crazy cheap.
Therefore the cheapest way to do ball twist is to just put two sensors and use the error as the twist amount. You could use a singular high resolution highspeed camera pointed at the ball instead, but that won't be the cheapest way to do it.
With only one you can't detect rotation around the axis that goes through the sensor, and for rotation close to that axis the resolution will be very poor.
Okay, sure, but that's a very narrow and specific angle though? Not sure I could deliberately rotate the ball in that direction even of I wanted to.
Especially given the limited use kensington uses rotation for (at least to my knowledge)
What about using 3 or 4 instead?
The Kensington SlimBlade scrolls when you rotate the trackball.
https://rotatrix.com/ Does pretty much that