Polar in Cartesian or what’s the use of rings of coins
Hi, Hiktames. A lot of water has flowed since I wrote here last time, almost 8 years ago. But it so happened that the next turn of fate threw me from an enikeyschik into an enthusiastic jeweler, and now I have something to tell and share again. And also there is something to ask the community, but first things first.
The idea to write me was prompted by a post a year ago about rings made from coins by Mr. Alizar. And it seemed to me that I could reveal the topic in more detail, from the inside and even adding a little bit of geekiness (although I didn’t reach the compression by the electromagnetic impulse yet, I confess).
And so, let's imagine that we have a coin. Flat, extruded from two sides. And let's say we want to make a ring out of it. At the same time, what is important, keeping the original drawing of the coin. You can do as in the original post - just knocking on the edge of the coin with a spoon, flattening the plane in another plane. But at the same time, which is logical, the pattern is lost. Therefore, it is necessary to include a section of the brain responsible for the topology of objects and go the difficult way of homeomorphism.
')
Simply put, in the coin it is necessary to knock out the middle, and bend the resulting washer 90 degrees relative to the main plane, by simultaneously stretching the central region and compressing the outer circumference. Gifkoy it looks much clearer:
Actually, for the sake of this gif I designed this post. For a very long time, I went to her - two years, almost to my liking. The first thought arose when I made the very first animation of copper kopeks and wanted more. But then I did not know how to work with silver coins (they were simply torn due to improper annealing). At the same time, American masters made rings from "Morgan" to "one-two", which led me to the idea of not giving up attempts. Six months later, I learned how to work with silver, but a second problem arose - the size of the coin. For the technologies existing at that time in my workshop, the coin was too big, 38 millimeters is not a joke. But this circumstance was overcome (the biggest coin with which I worked at the moment is the British crown of 1937, 38.6 mm). True to the gif was still far away. One thing is to learn how to make rings of such a coin, another thing is to find the time, place and situation to photograph the creation process. I will not describe the typical everyday problems, everyone knows them, but they took a few more months.
And so, a few days ago it finally happened. Three hours of production and filming, five hours of processing and creation, a total of 8 hours of work for a 15-second animation. Awesome efficiency. Tag sarcasm.
As for the technology itself in terms of a plastic hammer, a bolt, straight arms, and such and such a mother. I do not know whether it makes sense to paint it in detail here. It is not difficult for me, but is it necessary? Still, the subject is not quite profile. If really interesting - ask, I will answer with pleasure.
It seems to me that it is much more interesting to ask people and discuss the problem from the heading - the transformation of the polar coordinate system into Cartesian. The idea is to create, write or take ready-made code for the following:
- There is a coin.
- She has a drawing in the form of a circle on one of the sides.
- It is necessary to cut out the middle of the specified diameter from this drawing and pull the remaining washer onto the 3D model of the ring (break the texture in one place, squeeze the bottom, stretch the top; polar to Cartesian)
- Give the user the opportunity to twist this ring with the texture.
Simply put, you need a constructor into which you can upload a photo of a coin, and get a ring model at the output. The thought about it warms me even more time than the creation of a gif, but so far I have only learned to expand the texture in Photoshop in a strip, the curvature of my hands further exceeds the allowable limit.
This somewhat confused text came out, and even realizing that it breaks off at some hypothetical middle, however, I cannot figure out how to harmoniously expand or continue it, although, of course, there is something to tell. So, I hope, according to the good tradition of Giktime, in the comments there will be an equally interesting continuation.
The idea to write me was prompted by a post a year ago about rings made from coins by Mr. Alizar. And it seemed to me that I could reveal the topic in more detail, from the inside and even adding a little bit of geekiness (although I didn’t reach the compression by the electromagnetic impulse yet, I confess).
And so, let's imagine that we have a coin. Flat, extruded from two sides. And let's say we want to make a ring out of it. At the same time, what is important, keeping the original drawing of the coin. You can do as in the original post - just knocking on the edge of the coin with a spoon, flattening the plane in another plane. But at the same time, which is logical, the pattern is lost. Therefore, it is necessary to include a section of the brain responsible for the topology of objects and go the difficult way of homeomorphism.
')
Simply put, in the coin it is necessary to knock out the middle, and bend the resulting washer 90 degrees relative to the main plane, by simultaneously stretching the central region and compressing the outer circumference. Gifkoy it looks much clearer:
Gif
Actually, for the sake of this gif I designed this post. For a very long time, I went to her - two years, almost to my liking. The first thought arose when I made the very first animation of copper kopeks and wanted more. But then I did not know how to work with silver coins (they were simply torn due to improper annealing). At the same time, American masters made rings from "Morgan" to "one-two", which led me to the idea of not giving up attempts. Six months later, I learned how to work with silver, but a second problem arose - the size of the coin. For the technologies existing at that time in my workshop, the coin was too big, 38 millimeters is not a joke. But this circumstance was overcome (the biggest coin with which I worked at the moment is the British crown of 1937, 38.6 mm). True to the gif was still far away. One thing is to learn how to make rings of such a coin, another thing is to find the time, place and situation to photograph the creation process. I will not describe the typical everyday problems, everyone knows them, but they took a few more months.
And so, a few days ago it finally happened. Three hours of production and filming, five hours of processing and creation, a total of 8 hours of work for a 15-second animation. Awesome efficiency. Tag sarcasm.
As for the technology itself in terms of a plastic hammer, a bolt, straight arms, and such and such a mother. I do not know whether it makes sense to paint it in detail here. It is not difficult for me, but is it necessary? Still, the subject is not quite profile. If really interesting - ask, I will answer with pleasure.
It seems to me that it is much more interesting to ask people and discuss the problem from the heading - the transformation of the polar coordinate system into Cartesian. The idea is to create, write or take ready-made code for the following:
- There is a coin.
- She has a drawing in the form of a circle on one of the sides.
- It is necessary to cut out the middle of the specified diameter from this drawing and pull the remaining washer onto the 3D model of the ring (break the texture in one place, squeeze the bottom, stretch the top; polar to Cartesian)
- Give the user the opportunity to twist this ring with the texture.
Simply put, you need a constructor into which you can upload a photo of a coin, and get a ring model at the output. The thought about it warms me even more time than the creation of a gif, but so far I have only learned to expand the texture in Photoshop in a strip, the curvature of my hands further exceeds the allowable limit.
This somewhat confused text came out, and even realizing that it breaks off at some hypothetical middle, however, I cannot figure out how to harmoniously expand or continue it, although, of course, there is something to tell. So, I hope, according to the good tradition of Giktime, in the comments there will be an equally interesting continuation.
Source: https://habr.com/ru/post/403125/
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