Artificial Audio Quartz VST 1.0.2.53
Cherly Fleitas
Quartz, though, is at least a partial exception to this rule. Once its unusual electrical properties were understood, crystalline quartz was sent directly from quarries and mines to factories, where they were turned into piezoelectric devices with no chemical transformation whatsoever. The magic of crystal formation had already been done by natural processes; all that was needed was a little slicing and dicing.
Aside from its aesthetic charms, and disregarding the claims of mysterious powers made by crystal enthusiasts, quartz has a lot of industrial uses. Its abundance of silicon makes it the perfect feedstock for silicon wafer production, and fused quartz glass of nearly pure silicon dioxide is used for everything from optical communication fibers to the crucibles used to melt silicon for the Czochralski method of growing monocrystalline silicon ingots.
The piezoelectric effect, a property of certain crystals to vibrate at a characteristic frequency when a voltage is applied across them (and vice versa), has been known since the experiments of the Curie brothers in the 1880s, with quartz being one of the main crystals they focused on. Piezoelectricity first proved its utility in World War I, with submarine warfare and the need for ultrasonic transducers for sonar. Shortly after, the twin post-war explosions of radio and telephone increased the demand for quartz crystal oscillators. Almost all of the quartz needed for these components was harvested from natural crystals, mostly from Brazil and the quarries in Arkansas, from which raw slabs were painstakingly cut, polished, and processed to make finished piezoelectric components.
But then along came World War II, and the demand for natural quartz crystals exploded. Quartz was a critical material for prosecuting the war, and the supply of natural quartz was only barely keeping up with the demand, especially since crystals had to meet stringent requirements of purity and physical characteristics, such as lack of cracks and inclusions. It was clear too that the post-war period was going to see an even greater demand for quartz thanks to a burgeoning consumer electronics market, as well as continued expansion of the telephone network and the newfangled televisions that were coming along.
Seeing the intensely manual process of harvesting natural quartz as a threat to the future of the telephone network, engineers and scientists at Bell Labs, the R&D arm of AT&T, started research in the late 1940s into commercial-scale methods for making artificial quartz crystals. Artificial synthesis of crystals has been around since the late 1800s, but only on a microscopic scale. They needed a way to grow big crystals, and a lot of them, with bonus points if the method was cheap and easy to scale up to industrial levels.
Into the slurry in the pressure chamber is lowered a sturdy frame to which several thin sheets of quartz have been attached. These sheets, cut to the proper crystal orientation for the desired piezoelectric property, serve as the seed crystals upon which the synthetic crystals will grow.
I remember my time serving as conscript in 1984-1986, mostly assigned to vehicle maintenace. We had a couple of very large off-road MAZ trucks which were used to haul trailers with T-55 tanks. Those things had exhaust valves with quartz rim for seal, apparently to better protect againt heat damage. Unfortunately they also had tendency to chip and were royal PITA to replace. Apparently by 1989 they were reverted back to use standard tank engines with fuel efficiency of a bonfire.
Fused silica is essentially the same stuff as fused quartz but is noncrystalline. Fascinated by this stuff ever since I heard about Vycor, the brand name for a type of fused silica that can be heated red-hot, then plunged into water without damage.
Judy G....I don't know that I'm "wrong" that quartz looks fake to my eyes. When at the stone yard, I can spot the quartz isle a mile away.
I've been to numerous granite warehouses and seen so many slabs I'm dizzy. Some types are fairly good imitations, but there is no comparison between real marble/stone and manufactured quartz. To my eyes they look like plastic, especially the ones that have a lot of white. And a lot of the imitations of Calacatta Gold....yikes. Don't get mad at me....can't help it that the manufactured look is glaring to me. That's just what my eyes see.
These buffers typically contain hundreds or even thousands of samples at a time. It is important to understand that audio engine rendering commands are typically consumed at the beginning of an audio buffer render. A command, for example, might be to play a new sound, stop an old one, or change the parameter of a sound like volume or pitch.
Because of this, the size of the rendered audio buffer directly controls the rate at which new commands are consumed. This rate also describes the perceived audible latency of any issued commands. For example, if you were to trigger an explosion VFX and an explosion sound on the same game-thread tick, the latency between seeing the VFX explosion and hearing the sound is determined by this buffer size.
In addition to this inherent latency with an audio renderer due to the render buffer size, audio commands issued from the game thread take time to get to the audio engine due to game-thread and audio-thread ticks, and general thread communication overhead. If a threading or gameplay latency is 13 ms (a feasible number), and we use the same buffer size of 2048 samples at 48 kHz, and if the command just missed the start of the current buffer being rendered, there will be a worst-case accumulated latency of 56 ms.
If an audio request comes in after a buffer has started to render (1), then the request will carry forward without playing (2) until the beginning of the next buffer (3).
Game-thread ticks are also timed for gameplay and graphical rendering, not for audio rendering and audio timing. If you need to play a sound at a precise moment in time (exactly when a different sound is finishing or starting), calling that command from the game thread will not work because the game-thread and audio render-thread event timings are decoupled.
These issues of variable latency and game-thread-dependent timing of audio events are not significant for the majority of audio applications. Depending on the CPU load of a game or the constraints of a particular platform, it is usually possible to tweak the buffer sizes and number of buffers rendered ahead of time to a size where most timing issues are below the threshold of perception.
Quartz is a system that works around the issues of variable latency and game-thread timing incompatibility by providing a way to accurately play any sound sample. Sample accuracy refers to the ability for a sound to render audio at an arbitrary sample (point in time) within an audio buffer rather than at the beginning of the buffer.
Instead of rendering a sound at the beginning of an audio buffer, Quartz cues the sound to play on the desired musical value (bars or beats) or time value (seconds), independent of the buffer size, game-thread timing, or other sources of variable latency.
With Quartz, you can give the audio engine advance warning by scheduling a sound with PlayQuantized(), which executes the play command at a specific sample in the audio render. By scheduling ahead of time, you account for the delay so that sounds can render on exactly computed samples to make the queued-up sounds play as though there were no delay.
A represents the game thread, with X-axis demarcations indicating game frame ticks, while B represents the audio render thread with X-axis demarcations indicating rendered audio buffers. Their respective X-axes vertically line up in real-world time. (1) When the game thread calls PlayQuantized(), it requests that the sound be played on a given quantization boundary (such as the next quarter note), as calculated to the nearest audio output sample on the audio render thread. (2) Quartz issues this request in the form of a generic Quantized Command, and queues the sound for audio rendering at a future point in time. The request is held through multiple audio buffers on the audio render thread (3) by the computed amount. When it is time to render the sound in the computed buffer, Quartz feeds the audio through an integer delay that prevents it from rendering at the beginning of the buffer (4) and instead renders partway into the output buffer on the sample needed to play exactly on the quarter note (5).
A clock is the object in charge of scheduling and firing off events on the audio rendering thread. A clock is created with the Quartz Subsystem, and modified via a Blueprint using Clock Handles. Each clock has a Quartz Metronome.
The metronome is the audio render thread object that tracks the passage of time, and decides when upcoming commands need to be executed (from user-provided information such as BPM (beats per minute) and a time signature.
In addition to subscribing to various stages of a Quantized Command life cycle to synchronize gameplay with audio rendering, you can also get notified each time a Quantization Duration occurs.
California is poised to become the first state in the country to adopt special measures to protect workers who make kitchen and bathroom countertops out of a popular kind of artificial stone known as "quartz."
That's because more and more countertop workers, almost all Latino men, are coming down with an irreversible lung disease after breathing in dangerous dust while cutting and grinding quartz and other stone materials.
The disease, silicosis, is caused by silica dust that can fly into the air when a raw slab of countertop material gets cut to fulfill a customer's order. While natural stone like granite contains silica, "engineered stone" made of quartz contains far more, and public health experts have been warning of its increased risk.
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