View Full Version : How do you get a magnifying glass effect?

Steve Warner
09 September 2002, 03:15 AM
Hi all,

I'm wondering what surface setting I would use to get the effect of a magnifying glass. Is it a relfection thing or a refraction thing? Or am I way off base in assuming it's a surface issue?

Thanks for any help you can provide!


09 September 2002, 03:27 AM
it's a refraction thing.....I did a tut for Inspire awhile back that covered just this thing....let me see if I can track something down for u....

09 September 2002, 03:29 AM
old school tuts but not the right ones...I'll look some more:

09 September 2002, 03:51 AM
Just did a quick test...I maped an image on a flat plan and created a pill shape object......I placethe pill shaped object in front og the image mapped plane ...I used these settings

Transparency: 100%
Refraction: 1.8

worked like a magnifying glass......

I came up with that setting from looking in the Manual

Chapter 31.12: Great chart for refraction settings....hope this helps...

Steve Warner
09 September 2002, 02:52 PM
Thanks, Proton. I looked in the manual and saw refraction settings for glass, but didn't come across anything that said "refraction for magnifying glass." Figured I should ask.

Thanks again! I'll give these settings a shot this morning.


09 September 2002, 03:38 PM
Producing the Magnification Effect
Producing the effect of magnification is actually very easy. All you need to
do is keep the geometry of the lens in mind. A lens is simply a piece of
glass that has been shaped in a special way. If you look at a lens, it bows
out on both sides.

First, set the color of the surface to something appropriate for glass, perhaps
172 for the red component, 187 for the green, 200 for the blue.

set the Diffuse level to 95% to place some imperfections in the glass. Set
the Specular level 75%, as glass reflects light very well and thus does not
absorb much, thus preventing the light from spreading very much on the

Next, set the glossiness to high. Set the reflectivity to around 5%.
This is uncharacteristic of glass, but given the high specularity, setting the
reflectivity too low keeps the object from becoming too bright. To add
some more abstract reflections from other objects in the environment, go to
Reflection Options and select Spherical Reflection Map from the pull-down

Now, set the Reflection Image to fractal reflections.tga. Doing so
will reflect this random texture on the lens. And, as this is glass, set the
transparency to a very high value, such as 95%.

Now, for the heart of the
effect. Set the refractive index to 1.55. This will bend the light to a high
degree, distorting the image underneath, but coupled with the convex
nature of the lens, creates a magnified image.

Now, in the render panel, make sure
Trace Refractions checked, and render the scene.

Enter the following
values into the
Surfaces Panel:
Texture Color:
R:172, G:187, B:200
Diffusion: 95%
Specularity: 75%
Glossiness: High (256)
Reflective: 5%
Transparency: 95%
Refractive Index: 1.55
Smoothing: On
Double Sided: On

Steve Warner
09 September 2002, 07:43 PM
Thanks, Proton! I tried out the settings you listed earlier and did get a magnification effect. I'm looking forward to trying out this tutorial. :thumbsup:



Rumpus King
09 September 2002, 07:49 PM
Um. Is there a specific reason you're doing it in 3D? Every compositing program out there has some sort of image-distorting feature. It seems to me you could just render it, save the time it would take to render w/ refraction turned on, and just fix it in post.


09 September 2002, 07:53 PM
Steve....If it worx for you maybe you could make it into a full blown tutorial...:D

Steve Warner
09 September 2002, 09:29 PM
Rumpus King, I originally was going to do this in After Effects, but later realized that due to the way the magnifying glass moves, it would be better to do this in 3D. Unfortunate, as it will take longer to render. But better for me as the client will be happier with the results of the overall animation. :)

Proton, how can I resist? :D


09 September 2002, 09:45 PM
If you do it in 3D versus a comp program... you have a bit more freedom. -- It's been a while since I modeled / rendered this out... infact I don't really remember much even how I did the surfaces... but imagine this in an animation. :)

09 September 2002, 01:22 AM

09 September 2002, 01:27 AM
yeah...that's in teh manual

CGTalk Moderation
01 January 2006, 05:00 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.