atom feed8 messages in com.googlegroups.sketchupsuggestionsAssisted Optical Ray Drawing -- in S...
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trisquinolineOct 10, 2008 3:16 pm 
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trisquinolineOct 13, 2008 12:52 am 
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catamountainNov 11, 2008 10:23 pm 
catamountainNov 18, 2008 6:23 pm 
Subject:Assisted Optical Ray Drawing -- in SketchUp
From:trisquinoline (
Date:Oct 10, 2008 3:16:27 pm

Being in optics research, I find SketchUp a wonderful tool to visualize ideas -- often involving complex geometries in optics. Especially, since there is currently a trend towards non-rotationally symmetric optics, where drawing a "section" is just not enough.. SketchUp is very useful for that and has changed communication a lot.

However, very often, a few optical rays have to be drawn into a sketch, to visualize the path, that light takes throuhg the reflections, refractions, etc. in the system.

It would be phantastic, to have a tool or realize a script, that could assist there. Taking out the tedium and guesswork of getting the angles right of such rays. I imagine, that this would also be a great help in teaching optics to students, in high schools and universities, since the optical design software, we typically use, is many thousands of Dollars too expensive for education...

Best, Trisquinoline

In the following I have outlined, how I could imagine the interaction for such a tool. Please comment, append, improve as desired.:

1.) Start a ray Draw a line with orientation (startpoint-endpoint) in 3D

2.) Hit [P] Selected line will propagate (be extended) until it intersects with a surface

3.) Prompt will ask for a keyboard entry

[x] reflection Ray will reflect on the current surface: Meaning a line will be drawn at the reflection angle from the current point to

the intersection with the next surface.

[i] internal reflection Same as [x], just to denote an internal reflection (for later extension)

[r/R] refraction Ray will refract on the curent surface: Meaning a line will be drawn at the refraction angle (Snell's law) from the

current point to the intersection with the next surface.

[r] refraction into medium of lower refractive index (default: n=1/ n=1.5) [R] refraction into medium of higher refractive index (default: n=1.5/n=1) [r1.2/1.4] assume "coming" form a medium with n=1.2 and "going" into n=1.4

[a] absorb Ray Stops. No further line will be drawn

Note: To make the system "lightweight", it will not check physical sanity of the design whatsoever. It is the users responsibility to keep track of which medium is on which side of the SketchUp surfaces and assign refractive indices accordingly