Hi, I am making a Bahtinov filter generator and encounter a strange phenomena where when I rotate objects not all objects are rotated:
As you probably know I am used to program in Python, but every now and then I test out Grasshopper, so it might be a noob issue.
And here rotated:
And then when I combine all and mirror I loose even more data…
BAHTINOV GENERATOR.gh (13.8 KB)
This is on Rhino 7
Version 7 SR37
And if I adjust the radius, hole width or distance, then it changes what objects are not rotated or not mirrored.
I found a thing that solved it and that is subtracting 0.01 from the filleting of the curves. Is that a bug since it fillets the curves, but fails to rotate the filleted curves?
as result of the Fillet you indeed get some invalid Curves, which are not mirrored / rotated because invalid
I also see you are using Combine Data with multiple streams in the same input, where instead you might want to use Merge connecting each stream to a different input (not that the result would change, it’s just for clarity: Combine data is not doing anything to the data in that definition, it’s just used as “data container”)
is something like this the final shape you are after?
Thanks, if Merge is better than Combine then I will switch to that.
I just used Combine for me to better understand (later on) what is going on.
And yes, this is the result. I use Grasshopper to generate the curves and then extrude that.
This way we can test out the best distances for the holes and the ribs + the angle of the rotated quadrants 
I have just started dabbeling with astro photography and did my first image stacking test last night. Seems like a fun thing to play with. And I bought an old Sony Nex that I will change the IR/UV filter to clear glass now this winter to see how full spectrum photography turns out.
Here is the updated script if you want to play with it:
BAHTINOV GENERATOR.gh (17.3 KB)
Hi @Holo
Thanks for the gh file very nice of you. Please post a few images of your results when you get a chance. Are you photographing aurorae as well?
There are also a few sites where you can input your lens information and get either an svg file or stl file to print Bahtinov filters.
Telescope Focussing Mask Creator in 2D and 3D
Bahtinov Mask Drawings generator webApps
RM
My pleasure
Yes, we get the northern light here too and had some nice evenings this autumn, but I didn’t take a lot of photos. I’ll see what I can find though.
Here’s the result of the first photostack of Orions belt I did as a software test (we have had cloudy weather since). We do get a fair amount of light pollution where I live as you can see, and I don’t have any filters for that, but at the cabin it should be pretty awesome this winter, hope to get some nebula colors then.
Hi @Holo
Nice work thanks for posting!
Wishing you well on your astronomical and night sky photography.
RM
