brsram

• brsram commented on makeorbreakshop's instructable Wooden Star Map / Nightlight11 months ago

An alternate: use black acrylic, cut holes using a laser (can take care of varying brightness using different sized holes) and illuminate as you did. Am going to try it out!

• brsram commented on gravitino's instructable Cylindrical Mirror Art1 year ago

I use reflective mylar coated on plastic (used for solar reflectors) pasted on PVC pipes. Works extremely well, as they are very reflective. Prolonged exposure can lead to marks on the film, I have used standard thin lamination to get over the problem. Does reduce the reflectivity, but it is still great!

In a sense, the calculation is straightforward but messy. Take a ray from your eye to a point on the mirror. Now draw two rays: one will be the continuation of the original ray, find out where it intersects a given vertical plane (xi, 0, zi) (for convenience chosen to be the xz plane). Second should be the reflected ray from the mirror. Find out where it intersects the horizontal plane z = 0 (xo, yo, 0). Then, a point at (xo, yo, 0) after reflection will appear to be at (xi, 0, zi). So, to colour the pixel at (xo, yo, 0), find out what is the pixel at (xi, 0, zi) in your image. You can do this for any shaped mirror: all you need to know is the equation of the normal to the mirror, this is required for finding the reflected ray. Please let me know if anyone needs more details. I have bee...

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In a sense, the calculation is straightforward but messy. Take a ray from your eye to a point on the mirror. Now draw two rays: one will be the continuation of the original ray, find out where it intersects a given vertical plane (xi, 0, zi) (for convenience chosen to be the xz plane). Second should be the reflected ray from the mirror. Find out where it intersects the horizontal plane z = 0 (xo, yo, 0). Then, a point at (xo, yo, 0) after reflection will appear to be at (xi, 0, zi). So, to colour the pixel at (xo, yo, 0), find out what is the pixel at (xi, 0, zi) in your image. You can do this for any shaped mirror: all you need to know is the equation of the normal to the mirror, this is required for finding the reflected ray. Please let me know if anyone needs more details. I have been fascinated by anamorphic art!

• After seeing your model, I too would love to make it, using laser cut parts. It appears that most of the parts are 2-d and hence can be laser cut. Would love to check out the .ipt files! I will try to convert them into .dwg or .ps files, if I am successful, would be easy to get them laser cut. Can you upload the files please?

• brsram commented on CitizenScientist's instructable Stoichiometry Manipulative2 years ago