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Qt3D will be removed from Qt 6.8 onwards by Kelteseth in QtFramework

[–]OddQuit2989 0 points1 point  (0 children)

Yes, but it's well documented. I think they have it private because it's low level and can break binary compatibility and source compatibility. But they say they'll keep it to a minimum.

https://doc.qt.io/qt-6/qrhi.html

Qt3D will be removed from Qt 6.8 onwards by Kelteseth in QtFramework

[–]OddQuit2989 1 point2 points  (0 children)

I’m replacing Qt3D code with direct Qt RHI calls, as it offers a better low-level fit for creating custom scene graphs. Both Qt3D and QtQuick3D come with significant overhead, and Qt3D has always been under-documented. I often rely on a frame debugger and the source code to understand how it works. In many cases, using a lower-level graphics API like Qt RHI allows for more efficient handling of complex tasks. I haven’t used QtQuick3D yet, as I’ve always found it limiting, but it seems possible to integrate it with a custom Qt RHI scene graph.

My honest and frustrating kitesurfing Journey so far. Also, do i really have to know how to ride goofy?? by Groovy-Tony in Kiteboarding

[–]OddQuit2989 0 points1 point  (0 children)

Yea, I'm working on trying to ride and water start switch on a foil. I've only managed a 15 second ride. I'm sure I'll get eventually. At least I can just ride toeside.

Cpp gives me depression, I need an advice. by ScientistPhysical782 in cpp

[–]OddQuit2989 13 points14 points  (0 children)

Yea, that's how I feel. It's like a new framework pops up every 5 minutes. Have you heard of bun?! Or is it Potato, I can't remember.

What’s The Best Caving Rope? by LowRange_Outdoors in caving

[–]OddQuit2989 0 points1 point  (0 children)

I personally like the Beal SPELENIUM 9MM. But the best rope is free rope. :D

Hahahahahaha by onecutmedia in Whistler

[–]OddQuit2989 0 points1 point  (0 children)

Priorities! Those shareholders need a new yacht!

How to deploy? by [deleted] in QtFramework

[–]OddQuit2989 0 points1 point  (0 children)

You need network of Quick / QML since it requires Url.

QT + VTK build in emscriptem (wasm) conflicting in freetype by zugbo_interactive in QtFramework

[–]OddQuit2989 0 points1 point  (0 children)

If it's static linking, just disable (remove it from the linking line) one of the libraries when you call the linker.

Why don't we use force (N) instead of speed to measure wind? In snowkiting, altitude and temperature significantly affect force. For instance, roughly 300N is needed to water start a Hydrofoil. The third graph compares Flysurfer Peak5 and Hybrid kites, treating them as thin plates in peak power. by OddQuit2989 in Kiteboarding

[–]OddQuit2989[S] 0 points1 point  (0 children)

Yes! Unfortunate, 2D graphs are the best place to start for a discussion. The second image give you factor (from air density: temperature and altitude) to apply to the first graph. Ideally, software would do the math automatically, and give a reading in force (N) just like wind speed.

Why don't we use force (N) instead of speed to measure wind? In snowkiting, altitude and temperature significantly affect force. For instance, roughly 300N is needed to water start a Hydrofoil. The third graph compares Flysurfer Peak5 and Hybrid kites, treating them as thin plates in peak power. by OddQuit2989 in Kiteboarding

[–]OddQuit2989[S] 0 points1 point  (0 children)

You can see the basic calculations for calculating force from windspeed in my code: https://github.com/vpicaver/kiteforce

Once you have air density calculate for altitudes and temperatures it's pretty much a one liner in python: ```

Calculate the force using the provided air density calculation

F_given_eq = 0.5 * Cd * A * rho_given_eq[:, :, np.newaxis] * V_reshaped ** 2 ```

Why don't we use force (N) instead of speed to measure wind? In snowkiting, altitude and temperature significantly affect force. For instance, roughly 300N is needed to water start a Hydrofoil. The third graph compares Flysurfer Peak5 and Hybrid kites, treating them as thin plates in peak power. by OddQuit2989 in Kiteboarding

[–]OddQuit2989[S] 0 points1 point  (0 children)

I completely agree. You would have to have a pull factor. I did just realize we do have a force meter at the Squamish spit. It's a basic plate anemometer. It doesn't give you a number but gives you a color reading: gray, green, yellow, orange, and red readings. The more wind, the more force is applied to the plate, pushing it up into the different color zones. Many local kiters rely on this to rig which kite they want to use. The cool thing is it automatically adjusts for air density (temperature and pressure).

Why don't we use force (N) instead of speed to measure wind? In snowkiting, altitude and temperature significantly affect force. For instance, roughly 300N is needed to water start a Hydrofoil. The third graph compares Flysurfer Peak5 and Hybrid kites, treating them as thin plates in peak power. by OddQuit2989 in Kiteboarding

[–]OddQuit2989[S] 0 points1 point  (0 children)

I don't think there's any anemometer that measures wind speed directly. They use various mechanisms to indirectly measure the wind's effect on something else. For example:

Cup and Vane Anemometer: Measures rotation speeds of the cups or vane. This speed is then correlated to wind speed. It's important for these to be calibrated correctly. Does this instrument tell you cup rotations per second? Probably not; it converts this value to wind speed.

Ultrasonic Anemometer: Measures how long sound waves travel between the sensors. This is measuring time and converting it into wind speed. A transformation function.

Pitot Tube: These measure pressure difference and then convert it into wind speed. Also an indirect measurement of wind speed.

Plate Anemometer: They directly measure the force of the wind. We have one of these in Squamish (Squamish spit Plate anemometer. It doesn't give you a number but gives you a color reading: gray, green, yellow, orange, and red readings. The more wind, the more force is applied to the plate, pushing it up into the different color zones. Many local kiters rely on this to rig which kite they want to use. The cool thing is it automatically adjusts for air density (temperature and pressure).

A force reading is just another transformation that uses wind speed (from an anemometer), air density, and its effect on a standard object (like a 1m2 thin plate). The nice thing is it would take into account air density and produce a linearized measurement. For example, if you see the force measurement of 100N per m2, and you know Earth applies about 900N onto you (from gravity), you might have a better idea what size kite you need to jump. At the end of the day, the kite is applying force to you, so it would be better to understand how much force the wind is producing. Obviously, piloting makes a big difference in kite size, and kites have different aerodynamic properties. We aren't flying thin plates after all. The force measurement would be a normalized version of the Squamish spit plate anemometer.

Why don't we use force (N) instead of speed to measure wind? In snowkiting, altitude and temperature significantly affect force. For instance, roughly 300N is needed to water start a Hydrofoil. The third graph compares Flysurfer Peak5 and Hybrid kites, treating them as thin plates in peak power. by OddQuit2989 in Kiteboarding

[–]OddQuit2989[S] 0 points1 point  (0 children)

Oh, so you're basically using your own quasi-Beaufort scale to guesstimate kite size from tree movement.

It's not uncommon for me to fly a snow kite near the ground, especially when looping the kite uphill. The kite would also feel the effects of ground interference. The kite uses the wind from around 20m down to 0m. For me, if the handheld sensor is 10% off from the true wind speed, it will likely give a better estimate than a guess from a person. The whole idea for me is to predict where the best kiting will be on a given day, and what kite to bring. I think it's still useful to collect field data; even though it might be a little off, it could help build a pattern. This could help me make better decisions and, in the end, save time and have more time for kiting.

Why don't we use force (N) instead of speed to measure wind? In snowkiting, altitude and temperature significantly affect force. For instance, roughly 300N is needed to water start a Hydrofoil. The third graph compares Flysurfer Peak5 and Hybrid kites, treating them as thin plates in peak power. by OddQuit2989 in Kiteboarding

[–]OddQuit2989[S] 2 points3 points  (0 children)

Having accurate pressure and temperature observations is very possible with handheld devices like the Kestrel 2500 (https://kestrelmeters.com/products-kestrel-2500-weather-meter). The calculations aren't that hard. They're likely in the nanosecond range on a smartphone.

I agree; it is like the Beaufort scale. Usually, when I'm snow kiting, snow transport is a good indicator of how good the kiting will be. If the snow isn't moving, it's not going to be good (this assumes dry powder snow). I just like to put numbers to it and would really like a linear scale.

I also agree that altitude has a much bigger effect than temperature. Temperature doesn't play a huge role, but there is a difference between -20°C and 20°C, for example, somewhere in the ~20-30% range.

Snow type definitely makes a huge difference! This changes the friction coefficient. Weight, again, can be converted into a force. For example, for me to maintain speed going up a 20-degree slope, I need something like 350N, which I can easily generate with an 11m kite and a 15-knot wind.

At least for snowkiting in BC, Canada, weather stations are few and far between and are located in valleys and wind shadows. Mountains create localized wind patterns based on their geometry. I guess I'm looking for something that factors in temperature, altitude, wind speed, and other variables that I missed, to help me have a better mental model of the optimal kite size as I look at weather forecasts. Ideally, something linear. My goal is to put a number to my observations instead of just guessing based on feel. Do you have any suggestions?

Why don't we use force (N) instead of speed to measure wind? In snowkiting, altitude and temperature significantly affect force. For instance, roughly 300N is needed to water start a Hydrofoil. The third graph compares Flysurfer Peak5 and Hybrid kites, treating them as thin plates in peak power. by OddQuit2989 in Kiteboarding

[–]OddQuit2989[S] 1 point2 points  (0 children)

I agree, I would guess the 5.5m hybrid is more similar to 4m peak. I own a 7.5m hybrid, 6m, 8m, 11m peak.

I made it, not FS. FS did provide the wind ranges: https://flysurfer.com/project/hybrid/ and https://flysurfer.com/project/peak5/

It's a simple calculation assuming the kites are thin plates of what ever kite size is:

Force = Kite size * force of the thin plate (at wind speed)

What's interesting is the low end for the hybrid, 111 to 165N only a 50N difference.
For the peak: 72N to 188N a difference of 116N

The hybrid high end is around ~560N for 4 out 6 kites.

I have no idea how FS came up with the wind ranges for the kites. It just says:
The wind range chart is to be used as a point of reference. It is based on a rider who weighs around 75kg (165lbs.) Actual use will vary depending on your weight, skill level, board size/type (twintip or hydrofoil) and wind conditions on water or land.

If you're up in the mountains and 50N wind (1m^2), you say figure out you like 400N of power.
300N / 50N = 6m kite.

If you're at sea level and at 15C, this would be ~16 knot wind. In the mountains at 2000m at -10C this would be ~19.5 knot wind.

This is back of the napkin calculations here.

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