Some findings
1. In the refraction texture we define, the variable called refractionratio of the material is actually the (refractive index of air/ refractive index of lens).
2. Then if we increase refractive index, refractionratio decreases. When refractionratio increases, the focal length also increases. So the behaviour of the lens and the refraction ratio is in accordance with the real world and the lens makers formula.
3. We can use any material with refractive index > 1 and we would get a good behaviour.
4. As the radius of curvature increases, the focal length increases as well.
5. When we put the object at a distance at less than the focal length we get no(virtual) image.

Progress.........

So here is what I have done so far with the lab and am stuck here thinking hard....

Features available
1. A proper environment to move about
2. An optic bench that has a scale to measure the values
3. The freedom to move the object and image pins along the optic bench using the slider in HTML
4. A lens that has dynamic cube mapping feature
5. Three modes
5.1 Prepare mode - You can see the whole room and make arrangement for the experiment
5.2 Inspect mode - Keeps the camera in position to check the lens views
5.3 Read mode - Helps you to take the readings easily from the scale
6. Facility to increase and decrease the refractive index - The value is available on the top in HTML

A free demo of the usage is below. Please visit the link
http://www.youtube.com/watch?v=mkJqHsOJHBw&feature=youtu.be

Why I ponder -
1. When the refractive index goes above 1, a rather strange thing happens
2. My doubt is that the focal length of the lens is dependent on the radius of curvature of the lens as well. Since the radius of curvature of the sphere used to build the lens has to be in same units as that in the scale of the environment, this can be the cause of the problem

The big problem - The units, it is really a headache. If I make a cube of side 2 in Blender, is it the same units in the three.js. If not then we will not get accurate values for measurements.
Onto this now........................

So...........................
We conducted a lot of experiments (physically) consulted some experts and finally was able to find out a proper way of implementing the physics in three.js. Read on.......

1. What is a lens??? A lens is basically a part of a sphere

2. What is the radius of curvature of a lens???
It is the radius of the sphere of which, it is a part.

3. What is the refractive index (u) of a lens.
In optics the refractive index (or index of refraction) n of a substance (optical medium) is a dimensionless number that describes how light, or any other radiation, propagates through that medium.

4. What happens when light passes through a lens???


The light bends depending on the radius and the u of the lens......

5. What is the focus of a lens?
It is the point where all the rays intersect the principal axis after convergence.

6. What happens when an object placed on side A is being viewed from different angles on side B???



The eye, the focus and the image is always lying on the same line.....
The reason for the displacement of the image is due to the curvature of the lens.

7. What is the relation between the focal length, the refractive index(u), and the radius of curvature(R).

This is related by the modified lens maker's formula
1/f = 2(u-1)/R
So from this it is evident that for a lens of constant refractive index, the focal length is directly proportional to radius of curvature. So this is what happens when the radius of curvature decreases.....



So these are some of the basic stuff that should be known to a developer who intends to build a virtual lab for the optics experiment......

Follow the link and watch a very basic fluid simulation in Blender 2.5
This actually works with all the 3 particle effects viz - domain, fluid and an obstacle.

Check it

This is my first try on fluid simulation in Blender 2.5...

More to come as my hands on animation is getting wet :)

The involvement in the project has been minimal in the past 3 to 4 months due to other engagements. And a glance over the development shows nil in the GLGE lighting features. That precisely has put us off on continuing with the framework.

A new choice has been "three.js" which gives marvellous results with lighting. Inspite of a small array of glitches and lacks, this poses to be a good platform for the virtual labs to base itself. So from here on in, three.js takes up the coding area in the pages..........