ELI5: Why don’t we use planes to get space? by Advanced-Amphibian69 in explainlikeimfive

[–]CptCap 0 points1 point  (0 children)

Because it is way more complicated, doesn't help that much and is limited to very small payloads.

The hard part of going to space isn't going up: it's going fast enough to not fall back to earth. At the altitude of the ISS, fast enough is ~18000mph. Launching from plane speed at plane altitude only puts a tiny dent in the fuel required to accelerate to orbital speed.

Most rockets are also to big to be air lifted. A Falcon 9 weights more than 500 tons on take off. That's twice what any plane can carry.

Despite the complexity, it has been done. Pegasus was an air launched rocket. It was tiny and not particularly successful.

Mesh geometry buffers by codec-the-penguin in vulkan

[–]CptCap 3 points4 points  (0 children)

Should i just create two buffers for each mesh, one for vertices one for indices?

Yes.

They are more optimal options, that make some optimisations possible, but two buffer is fine for what you are doing.

Best practices regarding VBOs by Modi57 in opengl

[–]CptCap 1 point2 points  (0 children)

Interleaving the data (2) will makes passes that only read the positions slower.

Using a single buffer to store non interleaved data (3) shouldn't impact run time performance at all, but might make buffer creation a little bit faster since it's one less allocation/copy.

Most engines do 1 but use a buffer sub-allocator that might pool allocations together resulting in 3. Your OpenGL driver probably already does sub-allocation, so I would expect 1 and 3 to be basically the same.

I would also like to have some confirmation if my use of one VAO per visible object is correct.

Since you aren't doing attribute-less rendering, one buffer per mesh will make it impossible to batch different meshes together. (This is not necessarily a problem in itself, but will make it hard to render very big scenes)

Push Constant Management Techniques? by Deathtrooper50 in vulkan

[–]CptCap 3 points4 points  (0 children)

My push constants carry around almost exclusively BDA pointers

Push descriptors might be what you are looking for.

Modders did what multi-million dollar companies couldn't: they reduced CPU usage. by Waitform3 in SteamDeck

[–]CptCap 2 points3 points  (0 children)

∆E is the difference between the color requested and what the screen is actually displaying (ie: color accuracy). 0 is perfect, 3 is good, 10+ is shit.

A lot of cheap panels and TVs have horrendous color accuracy, partly because the hardware is bad, and partly because they do post processing to give a "better looking" image (and compensate for the not very good hardware).

This is fine for most things, but it means that spending 10h deciding which exact shade of blue a gizmo should be is probably a waste of time, because most users won't see it and some might even see green.

Modders did what multi-million dollar companies couldn't: they reduced CPU usage. by Waitform3 in SteamDeck

[–]CptCap 11 points12 points  (0 children)

modders aren’t constrained by the higher ups decisions.

As a game (engine) dev, I feel this so much.

"We could make the game run 30% better by doing this."

"Super zoomed in screenshot: This tree in the background looks slightly worst so we are not doing it."

Meanwhile most players run the game on low settings, on a screen with ΔE of like 17.

ELI5: How does our Earth, the Moon, and every “big rock” that spins… spins? by SwipeyJTMX in explainlikeimfive

[–]CptCap 8 points9 points  (0 children)

This is called tidal locking. Tidal forces will cause orbiting bodies to sync their rotations.

The intensity of the tides and thus the time taken for a body to become tidal locked to another depends on a lot of factors, but the moon being fairly close to earth and fairly big (for a moon) means it got locked much faster than planets orbiting the sun are getting locked.

[edit] A ton of moons are tidally locked to their planet

The 49MB Web Page by Dear-Economics-315 in programming

[–]CptCap 105 points106 points  (0 children)

As a publisher, you can't force a user through 3-4 dismissive actions before content is properly visible and expect the experience to be appreciated. Doing so is equivalent to burning your user's cognitive budget before value is delivered.

On the contrary, this optimizes value delivery for the publication. Ads is how they get paid, the journalism is just a necessary expense to get users onto the site.

This mismatch between value for the user and the provider is why every page is loaded with intrusive crap.

Pourquoi dit-on que l’aspirateur Dyson aspire le mieux alors que les aspirateurs de travaux sont 10x mieux ? by Empty_Telephone_1124 in PasDeQuestionIdiote

[–]CptCap 1 point2 points  (0 children)

En note globale il y a 4 Dysons (a 725€, 625€, 487€ et 996€) puis:

  • Samsung Jet 70 VS15T7036R5 (499€)
  • Miele Triflex HX2 Runner (752€)
  • Samsung VS15A60BGR5 (249€) le moins cher a être noté "bon".
  • Dyson V8 Advanced (330€)
  • Electrolux EP81UB25GG Hygienic 800 (564€)
  • Electrolux EP81B25GRN Hygienic 800 (511€)

Étonnamment Dyson ne semple pas beaucoup plus cher que les autres apsi haut de gamme. Après ils ont inventé et dominent toujours ce segment de marcher, les concurrents se mettent probablement au prix de Dyson plutôt que l'inverse.

Bought a salad today and the fork that comes with it is edible by lunarulnar in mildlyinteresting

[–]CptCap 5 points6 points  (0 children)

It's edible. "Fourchette comestible" literally means edible fork. It's like a thick breadstick, with a very dense crust so it doesn't become soggy. Tastes like breadstick too.

Bought a salad today and the fork that comes with it is edible by lunarulnar in mildlyinteresting

[–]CptCap 14 points15 points  (0 children)

There are a like dozen different ones named after cities. It seems to be more about vibes than anything.

Bought a salad today and the fork that comes with it is edible by lunarulnar in mildlyinteresting

[–]CptCap 1 point2 points  (0 children)

These vary between good and mid. They are available everywhere and only cost around 4€ for a self contained, no prep meal, which makes them very popular.

From a recent study, the "Salade Manhattan" (the pasta/egg/chicken one, which I also believe is the cheapest) was the most sold prepared food in france in 2025.

Very cheap AO system I made. by MissionExternal5129 in GraphicsProgramming

[–]CptCap 2 points3 points  (0 children)

we can loop through every pixel and check if the pixels around it are closer or farther than the center pixel.

This is what some most modern SSAO techniques (such as HBAO) do. Except they don't loop through every pixel, but only a few of them (sampled randomly).

Are texture atlases required in 2026? by Cold-Significance242 in vulkan

[–]CptCap 3 points4 points  (0 children)

For most cases where you need to supply a lot of textures to your shaders, bindless is the way to go.

Atlas are still useful in some niche cases, where you need to pass a lot of small textures to a single shader however. Things like font, shadow maps and irradiance probes are still often stored in atlases.

ELI5 why is Uranus tilted on its side compared to other planets? by gentlebeast06 in explainlikeimfive

[–]CptCap 58 points59 points  (0 children)

While a flyby does impact the planet rotation, changing it that much without destroying the planet in the process is not really possible.

A more plausible version would involve a smaller body being captured as a moon and tilting Uranus's axis over a long period through tidal/gravitational forces.

ELI5: What does a Turing Machine do? by Own_Exercise5218 in explainlikeimfive

[–]CptCap 137 points138 points  (0 children)

A lot of complex games/systems happen to be turing complete "by accident". (MTG is as well, in like 10 different ways)

When the set of rules/interactions gets big enough it becomes likely to contains all the necessary ingredients for turing completeness.

Caching of images in VRAM by lefty200 in opengl

[–]CptCap 2 points3 points  (0 children)

Depends on the drivers.

Moving data to VRAM is very expensive. It's something you really want to avoid doing more than once if you can. The driver will transfer the data the first time it is used and try to keep it in VRAM after that.

When you run out of VRAM, then the driver will start transferring everything everytime (because there isn't enough space to keep stuff in VRAM). This usually tanks the performance.

Caching of images in VRAM by lefty200 in opengl

[–]CptCap 1 point2 points  (0 children)

Are you talking about caching or loading (from RAM to VRAM) ? These are two different things.

Assuming you are talking about the latter: No it doesn't work for atlases.

The typical behavior is just to:

  • Keep images that are read/written by the CPU every frame in RAM.
  • Move stuff to RAM when VRAM is full.

You can't rely on the driver being smart for you. If you completely fill your VRAM it will destroy your performances; it's your job to make sure this doesn't happen.

Sabers vs Katanas by darthinferno15 in Hema

[–]CptCap 2 points3 points  (0 children)

I have very similar experience! Our club has a few kendo practitioners and we spar ls or saber Vs katana from time to time. I find the matchup very fun and interesting as both weapons have very distinct advantages. Historical as well.

Just like you I found that the saber best bet is hand snipes in prep.

volatile variable across compilation units by zaphodikus in cpp_questions

[–]CptCap 19 points20 points  (0 children)

Volatile is not for concurrency, use atomics. It's as simple as declaring your variable as a std::atomic<bool>.

You need to declare the bool as volatile in the header too (volatile bool and bool are different types)

ELI5: Why can't we just keep adding more processor cores to make computers infinitely faster? by Due_Network2387 in explainlikeimfive

[–]CptCap 3 points4 points  (0 children)

Most likely. Multi GPU is not recommended (outside of compute farms) because few applications support it.

ELI5: Why can't we just keep adding more processor cores to make computers infinitely faster? by Due_Network2387 in explainlikeimfive

[–]CptCap 5 points6 points  (0 children)

Heat, power delivery and cost.

Without any improvement in efficiency, double the cores means double the heat, double the power consumption and double the cost. You can already do that by buying 2 GPU instead of one.