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Re:Why can’t you design noise in frequency space? by ajot on Thursday December 30, 2021 @08:59AM (#29736715)
What are the use cases of generating different kind of noises (e.g. white, blue and red)? I've only heard about them as background noises to fall asleep or focus while working/studying.

Is there something ininformation or signal theory that benefits from creating truly random (or random but with some structure to it like blue noise not having lower frequencies) noise? As a chemist, I always model real-world noise with a gaussian distribution, so I don't really get where this could br used.

Re:Why can’t you design noise in frequency space? by dahart on Thursday December 30, 2021 @10:53AM (#29737716)
One reason to use Blue noise in graphics / games / images is anytime you need a random number per pixel for, say, some Monte Carlo process, that will have a visible effect on the image and result in visible noise in the output. Using blue noise, the output will be visibly less “noisy” looking than when using white noise, due to blue noise having no low frequencies.

Blue noise is best for situations where you only have the budget for 1 or 2 samples per pixel. The very low sample counts is where it performs considerably better than white noise. If you integrate with many samples, tens or hundreds or more, then the advantage of blue noise over other “colors” diminishes.

The author of this post has some examples in other articles on his blog, for example using blue noise vs white noise for ray traced soft shadows. https://blog.demofox.org/2020/05/16/using-blue-noise-for-ray...

Re:Why can’t you design noise in frequency space? by littlestymaar on Thursday December 30, 2021 @09:11AM (#29736812)
Blue noise is useful for procedural generation, because it's what the human eye will naturally consider the “most randon” and the most pleasant. IIRC red noise appears when you have random walks or Brownian motion.

> As a chemist, I always model real-world noise with a gaussian distribution

Gaussian distribution is what you get when you have a lot of independent random events adding up (it's the central limit theorem), so it applies a lot in real life but it can also cause modeling issues if it's not how randomness appears in your system. (Please note that I have absolutely no knowledge on chemistry so I have no idea if it's something that could be relevant in your field)

Re:Why can’t you design noise in frequency space? by iamwil on Thursday December 30, 2021 @09:06AM (#29736780)
Blue noise is useful in games for generating more natural looking scenes. Here's an example of how to algorithmically place grass in the game "The Witness".

https://youtu.be/Ge3aKEmZcqY?t=965

So if you use white noise, it looks unnaturally clustered with patches. This is the part that discusses the noise.

https://youtu.be/Ge3aKEmZcqY?t=1385

Re:Why can’t you design noise in frequency space? by dnautics on Thursday December 30, 2021 @12:52PM (#29739124)
Chemist here too but my ex was an sound consultant for an architectural firm. Iirc, different kinds of noises essentially are defined by the average amplitude (energy) vs frequency function of the rng. For architects, it can be important to model noise to ensure your structure complies with for example OSHA regulations. There can be code regulations too if you're in an urban place and say putting residential on top of street level commercial spaces, especially bars that might be open late. Finally, for gathering/events spaces you want to have a situation where a PA/presentation system doesn't have to work hard to go over conversation noise.

The energy profiles for all of these scenarios is empirically determined and "well known" in the community.

The ex helped model the "death star" auditorium space at the academy of motion picture arts and sciences in LA. IIRC it sounds really aquarium-ey during normal times and during events they roll out strategically placed dampeners.

Re:Why can’t you design noise in frequency space? by anon_123g987 on Thursday December 30, 2021 @09:09AM (#29736805)
Also chemist here. Think about it the other way around, not synthesis but analysis. For example: "The term "Brown noise" does not come from the color, but after Robert Brown, who documented the erratic motion for multiple types of inanimate particles in water." (https://en.wikipedia.org/wiki/Brownian_noise)
Re:Why can’t you design noise in frequency space? by marktangotango on Thursday December 30, 2021 @09:21AM (#29736883)
Side note; what does a self described chemist do these days? Seems like Breaking Bad spurred a lot of interest in the field, but as someone who minored in chemistry many years ago, the actual job prospects seemed limited. And research seemed very stodgy (to me at least). If you don't mind sharing, what's your background and what types of things are you working on?
Re:Why can’t you design noise in frequency space? by whatshisface on Thursday December 30, 2021 @01:55PM (#29739978)
Chemists do the same things they always have, just for much less money than the same people would make today in software engineering. Here are some types of applied chemistry:

- Deciding what ratio to mix things in for the countless liquid products that are combinations of already-discovered chemicals. Everything at the grocery store that comes in a jug or a bottle (cleaning products, hair conditioner, drain cleaner) falls in to this category.

- Doing industrial research to improve existing processes. This would include discovering new catalysts, and trying out the endless permutations of solvents and conditions in which existing reactions take place, to optimize them for whatever the biggest operating costs are.

- Figuring out how to recycle industrial chemicals and get the valuable stuff back out of sludge and effluent. This is a surprisingly big field with important consequences.

- Working on specialty materials, like plastics and synthetic rubbers, that are not completely dissimilar from existing products but require a chemist to design them for specific, demanding applications.

The fact that everything involving the physical world gets you paid way less for work that's way more difficult than programming will come back to bite us somehow, but it's hard to say when.

Re:Why can’t you design noise in frequency space? by robocat on Thursday December 30, 2021 @07:36PM (#29743458)
> for work that's way more difficult than programming

That just reads as “I am better than you”.

Programming is arbitrarily difficult, and it rarely has an objective reality to measure against. I have some kind of “Peter Principle” in mind where people continuously reach their own personal limits of complexity. However they then expand their skills in an ill-defined problem space to level up and beat their prior limits. Programmers display a massive variety of talent, and most of the talent is invisible because the problem space is heinously deeply complex and outside observers only see glimmers on the surface.

Or is your implication that idiots and/or lazy people choose to be programmers? Certainly there is a share of them in the discipline too: perhaps smart for chasing money and perhaps even content with the challenges they face personally.

Regardless, you are being very judgmental towards programming.

Your own descriptions of your discipline could be perceived as rote work or make work, on the same level as making another CRUD app for a business, that doesn’t require deep applied intelligence. How people apply their skills and intellect to the problem defines how hard the problem is.

Then I think of https://library.sciencemadness.org/library/books/ignition.pd... which I read as a study in applied intuition in Chemistry at a genius level (with some survivor bias to boot!).

Re:Why can’t you design noise in frequency space? by whatshisface on Thursday December 30, 2021 @08:39PM (#29743871)
I personally have experienced the more-money-less-difficulty science-to-coding gradient. You can say that programming can be arbitrarily difficult, which is true, the reality is that it usually isn't arbitrarily difficult, and corporations are happy to pay non-geniuses lots and lots of money to reliably design systems that work with zero marginal cost, whereas if you want to make $160k as a ground-level researcher, making 1% improvements to products with very substantial marginal costs, using million-dollar equipment to do your job, you'd have to be a rare intellect indeed, and beyond that be great at selling your own value.

In software, there's no such thing as marginal cost, the only tool you need is a $300 laptop, and all you need to know can be read for free online. That's an amazing world, from an economic standpoint, and it's no surprise at all that it's so much easier to make money that way.

Re:Why can’t you design noise in frequency space? by analog31 on Thursday December 30, 2021 @10:14AM (#29737343)
I'm not a chemist. (Worse, I'm a physicist). But I have several relatives who are chemists. And I work for chemists. I think there's an issue right now, which is that market demand for computer programmers has created a distorted view of all other occupations. That's not going away any time soon, and if it does, there will be some other "hot" occupation.

I think what makes people want to become natural scientists is a genuine interest in how things work, plus either an innate or learned ability to "think" in a certain way that works for their field of study. I don't have a good way to describe it, but a sense that a chemist thinks like a chemist. A scientist is obsessed with learning how things work. The different fields are different approaches to finding that out, that work for their respective domains. Trying to figure out how a frog works by thinking like a physicist will result in a lot of dead frogs.

The other post mentions food science. Stodgy, yes. Fascinating, you bet. Food isn't going away. The problems of making food abundant, pure, healthy, safe, and ecological, are going to get more and more challenging. It can be stodgy because we have to control our impulse to try dangerous experiments on human subjects, or make a mistake that brings down a production line or triggers a recall. But oddly enough there are people who get their excitement out of working within that constrained environment.

You have to embrace the stodge. Something I've noticed about chemists, is that they tend to have the best discipline about running controlled, repeatable experiments. They keep the best notebooks.

Chemistry is closely related to materials science. Any realistic development of a material beyond the basic research phase will require the involvement of a chemist. Likewise drug manufacturing, etc.

Re:Why can’t you design noise in frequency space? by anon_123g987 on Thursday December 30, 2021 @09:48AM (#29737115)
I don't think Chemistry in and of itself is a thing, or was it ever. It always has to be applied to something, and then the possibilities are endless. After all, everything is made of chemicals, isn't it? Personally, I'm in food, I also have an MSc in Food Engineering, and currently preparing to start a PhD in that area (NIR spectroscopy, Hyperspectral Image Analysis). But there is also the oil, pharma, bio, environmental, etc. areas. (Also, in British English "Chemist" means "Pharmacist". I always wondered, what they called a Chemist?)
Re:Why can’t you design noise in frequency space? by KineticLensman on Thursday December 30, 2021 @11:59AM (#29738394)
> Also, in British English "Chemist" means "Pharmacist". I always wondered, what they called a Chemist?

(Brit here). A shop that sells pharma products is often colloquially called 'a chemists' but the people who work there are typically referred to as pharmacists. 'Chemistry' as studied at school and Uni is totally about chemicals in general and not drugs (which would be pharmacology). Someone who described themselves as a chemistry student or professor would almost inevitably be perceived as someone who is working with chemicals.

Re:Why can’t you design noise in frequency space? by anon_123g987 on Thursday December 30, 2021 @12:10PM (#29738519)
OK, thank you for clearing this up!
Re:Why can’t you design noise in frequency space? by ajot on Thursday December 30, 2021 @07:03PM (#29743177)
Most jobs in industry are in quality control for medicines, food, paint, cleaning products, etc. Most industries need at least one chemist to analyse input and output to your processes. Then you have academia/teaching.

Myself, I'm about to finish my PhD in materials science and discover what I can really pivot to, wether related to materials/chemistry or using what I've learned about data analysis for any other area.

Re:Why can’t you design noise in frequency space? by kwijybo on Thursday December 30, 2021 @04:00PM (#29741373)
I'm a chemist. I've done a lot of food, beverage and water testing. Now I test dirt
Re:Why can’t you design noise in frequency space? by PragmaticPulp on Thursday December 30, 2021 @09:15AM (#29736845)
The difference is the spectral power distribution of the noise.

White noise has a flat spectrum from low to high frequencies. It has the standard noise sound that most of us recognize from digital systems.

Pink noise is shaped with a decreasing power as frequency increases. This results in more low frequency noise and less high frequency noise. This noise pattern occurs frequently in natural systems.

Different colors of noise have different sounds to our ears, of course. The color naming scheme is loosely intended to map to light spectral distributions. For example, blue noise has a rising power with increasing frequency, similar to how blue light has more energy at higher frequencies (shorter wavelengths).

Re:Why can’t you design noise in frequency space? by HelloNurse on Thursday December 30, 2021 @09:55AM (#29737167)
Different spectrums can be tailored for signal processing schemes that want to add more noise at frequencies that need it and remove the noise with a filter when it has served its purpose. For example dithering adds enough extremely high frequency noise to obliterate unwanted patterns, then applies a lowpass filter that keeps all the "good" signal and removes the noise.
Re:Why can’t you design noise in frequency space? by ocharles on Thursday December 30, 2021 @09:06AM (#29736775)
For one real application of blue noise in particular, see https://youtu.be/Ge3aKEmZcqY?t=1350 (22:30 is a good starting point). Here Casy explains a grass planting algorithm for games, where white noise wouldn't be suitable.
Re:Why can’t you design noise in frequency space? by iamwil on Thursday December 30, 2021 @09:07AM (#29736783)
Haha, I guess you and I just saw the same video.
Re:Why can’t you design noise in frequency space? by jarenmf on Thursday December 30, 2021 @09:15AM (#29736847)
Sometimes certain measuring instruments can be assumed to have such profiles for noise, in this case generating noise is useful for Monte Carlo based modeling or uncertainty propagation.
Re:Why can’t you design noise in frequency space? by the__alchemist on Thursday December 30, 2021 @09:04AM (#29736749)
I'm using pink noise in an audiogram, to determine if users can hear sounds with it as background.
Re:Why can’t you design noise in frequency space? by mzs on Thursday December 30, 2021 @05:10PM (#29742103)