Referencing driven dimentions

saule_karavirs

First off, I have seen many forum posts about using variables to make a know driving dimension adjustable.  That is not my question.

I am trying to design an optical system by modeling light rays passing through the various elements.  I use a formula to model the refracted angle of light based on the angle of incidents of the light ray hitting the optical surface.  The issue is, that angle of incidents is a driven variable.  The shape of the surface is the driving variable and the angle of incidents is driven.  So the angle of incidents cannot be a variable that I make before the sketch.  Because of this, I have to go through and manually take down the angle value at the time of creating the driven dimension so that I can later put it into the formula for the refracted angle.  Is there a way to reference the driven dimension so that it updates automatically as I change surface shape?  In other software, each dimension had a label such as "D1" or "Dx" that can be referenced by any other dimension in the same sketch.  Is there anyway to do that or something similar?

For context on how this works: I do this work in one sketch and when I have the optical system working how I want it, I revolve the sketch and export my parts.

Thankyou for any input.

S1mon

It might be easier to use this custom feature to do some basic ray tracing:
https://cad.onshape.com/documents/258a19506c555f400614c944/w/74e657ae2800105e2874589a/e/06cda6b388025780ed52a757

rafael_telgmann

Hi, with the FS Measure Value you can create variables from measured angles. Is this what you are looking for?https://cad.onshape.com/documents/77baa8153589a7fc5f289829/v/5156e9da7c3dd0dd87e3280a/e/56ddbb80665431f0cb57dbaf

S1mon

It might be easier to use this custom feature to do some basic ray tracing:
https://cad.onshape.com/documents/258a19506c555f400614c944/w/74e657ae2800105e2874589a/e/06cda6b388025780ed52a757

saule_karavirs

Simon, I am unable to load that feature propperly.  It shows only a dark grey screen with a downloadable pdf, and some text that says the program is view only.  Although, there does not seem to be a way to view it.

rafael_telgmann

Hi, with the FS Measure Value you can create variables from measured angles. Is this what you are looking for?https://cad.onshape.com/documents/77baa8153589a7fc5f289829/v/5156e9da7c3dd0dd87e3280a/e/56ddbb80665431f0cb57dbaf

S1mon

You need to be signed into your account, and then there is an "[+] Custom features" button at the top that you can use.

saule_karavirs

Thankyou both.  I have managed to get the ray tracer working and it helps for this project.  The other one seems more like what I was asking for, and I will soon try to get working as well, I can see many other applications for that type of measurement and dimensioning.