09-22-2021, 01:30 PM
I continue with the Simple harmonograph plugin. I show some Simple examples. First I show what I meant when i wrote "I like to think that the primary motion is slow and large, and the secondary is faster and smaller and adds some frills to the slower primary motion." Look at the picture on the left:
On its own, the primary motion would make a perfect circle (it is a circular motion by definition). But here there are some frills (cusps, sharp points) along the circle. They come from the secondary motion. I made this with otherwise the default inputs except that I set:
Below, the first is made with Primary=1, Secondary=2, Opposite=No, Ratio=1.5, Spin=3, No damping, Cycles=60. The other one is the same with Damping mode=Linear, Amount=10.
The next two are done with the same inputs as those above except that Opposite=Yes.
When you start experimenting, sometimes you get a mess and sometimes something good and surprising, but there is no easy way to tell from beforehand.
Below are some random tries. Top left: Primary=1, Secondary=7, Opposite=Yes, Ratio=7.0, Spin=0, No damping.
Top middle: The same but with Damping: Mode=Linear, Amount=10, Cycles=25.
Top right: The same with Ratio=3.5, Spin=4, Damping mode=Linear, Amount=10, Cycles=25.
Bottom left: Primary=1, Secondary=3, Opposite=Yes, Ratio=8.1, Spin=0, No damping.
Bottom middle: The same with Damping mode=Linear, Amount=10, Cycles=25.
Bottom right: The same with Spin=15, Damping mode=Exponential, Amount=10, Cycles=80.
That bottom left picture amazes me. Can you imagine such figure, with those practically straight edges, coming from two circular motions? I cannot. An animation would help.
I finish this already too long post with a case where I tried to re-create a certain curve with my plugin. The curve is in the poster of Hitchcock's Vertigo. I got rather close.
The recipe is: Primary=1, Secondary=1, Opposite=Yes, Ratio=6, Spin=8, Damping mode=Linear, Amount=8, Cycles=45. Then I scaled the path a little to make it rounder, and finally I rotated it a little.
When you are experimenting and you happen to get a nice curve which you would like to re-create later, do as follows: Re-run the plugin with "Display messages" set to "Yes". Then in the error console you see the parameters that were used. Copy them from the console to some file and save.
Note: My algorithms are not perfect. Sometimes faults occur, like getting small loops where should be cusps (sharp points). Then you can try to change your inputs a little. For example change Ratio=7.0 to Ratio=7.1. By the way, the rule for creating cusps is: When there is no spinning and no damping, setting Ratio to
Ratio = (Secondary frequency) / (Primary frequency)
you get cusps. If there is some spinning or damping, I cannot solve the exact rule, but you can try the same formula. It seems to create not-quite-so-sharp points.
On its own, the primary motion would make a perfect circle (it is a circular motion by definition). But here there are some frills (cusps, sharp points) along the circle. They come from the secondary motion. I made this with otherwise the default inputs except that I set:
- Primary frequency = 1.
- Secondary frequency = 10. This makes the secondary motion fast, 10 times as fast as the primary.
- Ratio of the radii (primary/secondary) = 10. This makes the secondary motion small, 10th part of the primary.
- Spin rate = 0.
Below, the first is made with Primary=1, Secondary=2, Opposite=No, Ratio=1.5, Spin=3, No damping, Cycles=60. The other one is the same with Damping mode=Linear, Amount=10.
The next two are done with the same inputs as those above except that Opposite=Yes.
When you start experimenting, sometimes you get a mess and sometimes something good and surprising, but there is no easy way to tell from beforehand.
Below are some random tries. Top left: Primary=1, Secondary=7, Opposite=Yes, Ratio=7.0, Spin=0, No damping.
Top middle: The same but with Damping: Mode=Linear, Amount=10, Cycles=25.
Top right: The same with Ratio=3.5, Spin=4, Damping mode=Linear, Amount=10, Cycles=25.
Bottom left: Primary=1, Secondary=3, Opposite=Yes, Ratio=8.1, Spin=0, No damping.
Bottom middle: The same with Damping mode=Linear, Amount=10, Cycles=25.
Bottom right: The same with Spin=15, Damping mode=Exponential, Amount=10, Cycles=80.
That bottom left picture amazes me. Can you imagine such figure, with those practically straight edges, coming from two circular motions? I cannot. An animation would help.
I finish this already too long post with a case where I tried to re-create a certain curve with my plugin. The curve is in the poster of Hitchcock's Vertigo. I got rather close.
The recipe is: Primary=1, Secondary=1, Opposite=Yes, Ratio=6, Spin=8, Damping mode=Linear, Amount=8, Cycles=45. Then I scaled the path a little to make it rounder, and finally I rotated it a little.
When you are experimenting and you happen to get a nice curve which you would like to re-create later, do as follows: Re-run the plugin with "Display messages" set to "Yes". Then in the error console you see the parameters that were used. Copy them from the console to some file and save.
Note: My algorithms are not perfect. Sometimes faults occur, like getting small loops where should be cusps (sharp points). Then you can try to change your inputs a little. For example change Ratio=7.0 to Ratio=7.1. By the way, the rule for creating cusps is: When there is no spinning and no damping, setting Ratio to
Ratio = (Secondary frequency) / (Primary frequency)
you get cusps. If there is some spinning or damping, I cannot solve the exact rule, but you can try the same formula. It seems to create not-quite-so-sharp points.