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Hi all,

This is a test i did in Maxwell a few months ago, but was kind of lazy to post it untill now.

SUMMARY

1. Pass a ray of light through a first prism to disperse and then pass the dispersed light through a second prism to disperse again.
2. Use standard (real life) dielectric material type SF-57, ND=1.847, Abbe=23.8
   http://www.edmundoptics.com/techsupport ... icleid=259

RESULT

• Maxwell output when superimposed with the theoretical light paths seems quite accurate.
  However there are a couple of things that are still a mystery, such as:
• Why is the first grouping arched instead of vertical, while the second and third grouping appear more straight ?
  EDIT: This has been mostly resolved. The behavior is correct as it apears in nature as well. It relates to the height of the colimator slit producing rays that are slightly not parallel as they reach the prism surfaces, thus bending at minutely different angles.
  Ref Photo: http://www.rit.edu/~andpph/photofile-c/ ... m_8661.jpg
• (In the beta 1.2.2a image) The second grouping is probably dispersion of secondary rays (since there are a lot of internal reflections happening inside the prisms and some of those reflections, at certain angles, they iventually escape). However, I am not sure yet which rays cause this grouping
• The third grouping is a little off from where it was expected (it is also possible that my schematic was not too accurate)
• The reflection seen through the second prism does not include the blue caustic that crosses the shadow of the light gun (not even after 1000 hours of rendering)

Output V1.1



Output Beta 1.2.2a




Download DXF file (simplified version)
Download MXS V1.1 file (simplified version)

Man, you're just insane. Looks fantastic, but I'll need some more time to understand. Holger

Very well done Thomas! and what's best of all is the presentation of this.

/ Max

So purty

Excellent tests, I'm sure you will be testing them with 1.0?

Is the lightsource in the "lightgun" just a plane emitter?

Mihai Iliuta wrote:Is the lightsource in the "lightgun" just a plane emitter?

Thanks Mihai. Yes, the source is a single plane.

Max, Holger,

Thank you for the comments

yeah good work mate - next year's nobel prize is yours

good. i'm trying to make out all that math stuff you scribbled over there. i'll let you know in a couple of weeks.

huh......????

rivoli wrote:good. i'm trying to make out all that math stuff you scribbled over there. i'll let you know in a couple of weeks.

Don't worry about it.
It is just a quick scribble to figure out the exit angle as the ray passes through the prism. (I wanted to draw the theoretical lines accurately)

Thomas An. wrote: Don't worry about it.

oh well, i feel a bit better now, it was like going back to school for a moment. as i told you when you first posted it: great picture (even if don't understand jack of what is going on).

rivoli wrote:

Thomas An. wrote: Don't worry about it.

oh well, i feel a bit better now, it was like going back to school for a moment. as i told you when you first posted it: great picture (even if don't understand jack of what is going on).

It is not really complex; it is geometry
Use the snell law twice (one for the first face of the prism and one for the other. It turns out (if I am not mistaken) that the angle between lines 2 and 3 is constant regardless of which point of the prism face is hit by line 2 (regardless of orientation).

So once you solve for one, the rest is easy... just reflections

Well, I have some questions too.

- What causes the beams on the ground? I think there's one more gun under the gun and they seem they are not parallel to each other.
- I cannot understand why the pattern is curved. (all is curved, some just seem vertical but not perfectly pay attention)
- Why beveled prisms? They seem artistically very nice to me, but I'm not sure if they make a bad trick.
- Is there a text on the prism, if yes, why?... if no, what is it about?

Yes, eyecandy test Thomas, thank you. If you can answer the above questions or make the scene more simple, maybe I can start thinking about it. IMHO, this is more art than a simple thing to discuss on it.

tom wrote:Well, I have some questions too.
- What causes the beams on the ground? I think there's one more gun under the gun and they seem they are not parallel to each other.
- I cannot understand why the pattern is curved. (all is curved, some just seem vertical but not perfectly pay attention)
- Why beveled prisms? They seem artistically very nice to me, but I'm not sure if they make a bad trick.
- Is there a text on the prism, if yes, why?... if no, what is it about?

Yes, eyecandy test Thomas, thank you. If you can answer the above questions or make the scene more simple, maybe I can start thinking about it. IMHO, this is more art than a simple thing to discuss on it.

Tom,

About, the beams on the ground: Are you refering to number 4 and 6 ?
These are expected by the analytical model. The schematic illustration was done before the render. Afterwards the images were superimposed and the beam locations coincide.

About emitters: There is only one emitter causing the beams. The other emiter is an overhead to iluminate the scene and has no effect on the dispersion.

About the bevels: They have a limited negligible localized effect. The previous version of this scene was done with no bevels and the light was taking the same paths and dispersion groupings. Since the bevels did not really alter the composition I left them in.

Text on the prism ? I don't understand this one. Can you explain ?

Hmm... well I think I have to examine more, because it seems complex for me to investigate the situation. I just can say, great scene!