The Physical Accuracy of Cycles - Simple Projector

Artwork Blender Tests
1

I wanted to see just how realistic Cycles is by trying to do what I learned in school about optics.

This is simply a plane with emission material with color set to an image texture, a lens with glass material with IOR at 1.5, and a big plane with white, diffuse material for a projection screen.

I had trouble making a lens that would work well. I ended up using the side of a UV sphere that I put a mirror modifier on, which makes for an ugly looking, but pretty well working lens.

I’m not sure these are the exact distances between the objects that would produce the sharpest possible projection, but it’s somewhere very close. You see, in Cycles, just as in real life, the focal length of the lens and the distances between the objects have to be just right in relationship to each other in order to create a sharp projection.

.blend: lens.blend (479 KB)

upload.png736×239 101 KB


2

Gotta love it. :slight_smile:

3

is it too trivial saying “this is cool”?

4

File please! This is amazing.

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.blend added to first post. :slight_smile:

6

Doh, I tried to create a lens to make real lens flares but couldnt model a decent shape for the glass. Never considered mirror modifier. Thanks.

BTW all I could manage was a focused hot spot for burning ants. I like what you have achieved here.

7

that is surprising, lens mesh is not even closed object . . .? hm

8

Yeah, I thought about that too…

9

I wonder if you could simulate a holographic sheet?

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The BLEND did not work for me, I just get a black render. What do I need to do to make this work?

11

you need to find (or open some) image for “projector” plane that works as emiter of light (not sure if it’s included)

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Yeah, the blend file is a lot smaller than the texture I used so it might not be included.

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I thought that might be the case. I did browse to another image and assign that to the plane material.
I even flipped the normals of the plane which are pointing the wrong way.

I still get a black scene using 2.6.1 r42722 CPU acceleration (no GPU detected).

14

this happens to me with newer cycles build, sometimes. try to create a new material.