This is an old topic (from the early Maxwell Alpha days), which appears referenced quite often even to this day. As such, maybe it would be more useful in this section instead of having to dig the archives.
-----------------------------------------------------TEST PERFORMED WITH MAXWELL ALPHA - 1.1.33
(This may have been discussed and conluded previously, but I wanted to do an independent confirmation)
This test involved the use of thin film dielectrics (membranes) to test Maxwell behavior.
- Incident dielectric membrane= When the surface normals are on the same side that the incident light hits.
- Non-Incident dielectric membrane= When the surface normals are on the oposite side from where the incident light hits.
- 1. Maxwell light is history aware (it remembers the dielectrics it has passed through). Think of it as a LIFO type stack (Last In First Out) collecting ND numbers each time it encounters an incident membrane.
- 2. Maxwell calculates refraction by using the ND numbers of the two previous incident dielectric surfaces as N1 and N2 for the snell law. (www). If there are no "previous" ND numbers then air is used.
- 3. The ND of the non-incident membranes are absolutely ignored. Non-incident membranes only act as "triggers" for using the previous ND as N1 (or N2 depending on how nested they are) for Snell's law
Two dielectric membranes with normals facing away from each other.
The ray deflection is evident (this image was alowed to render for 5h longer than the others and thats why it looks more well developed)Image-1b,1c:
Changing the ND of the second membrane (B) to see if it will affect the path of the rays.
The answer is NO. Maxwell is using the ND of (the previous) membrane A in all instances.Image-1d:
Does Maxwell use the ND of the previous memebrane regardless of the direction of the normals?
The answer is NO. Maxwell is using the ND of only the previous incident membrane
(which is the last membrane whose normals happen to be on the same side as the incident light rays)Image-2a,2b:
Are we sure that the incident membranes are the only ones that contribute to the Snell's equation ?
The answer is Yes. In image 2a the rays are not deflected, but in image 2b they are deflected.Image-3a,3b,3c
Does Maxwell remember the nesting of dielectrics ?
The answer is Yes. In images 3a,b,c all factors are the same as image 1a except a third membrane C is added.
In image3a the ND=1 (air) and the result is the same as image 1a
In image3b the ND=2.4 and now the result has changed correctly as Maxwell exits B from glass to glass therefore straight.
In image 3c the ND=5.0 and now the beams are correctly focused as Maxwell exits from B into a much thicker medium.Based on the above experiment, then the proper way to draw liquid-in-glass with Maxwell is as shown bellow:
- Intersection of ray R1 at point A evaluates as step1 Snell's law (in the propagation diagram). This is an incident membrane intersection and Maxwell treats this as an air-to-liquid interface
- Intersection of ray R1 at point B evaluates as step 2 Snell's law. This is also an incident membrane intersection and Maxwell (correctly) treats it as a glass-to liquid interface
- Intersection of ray R1 at point X1 evaluates similarly to step 5 Snell's law (of the propagation diagram). This is a non-incident intersection and the ND is irrelevant. Maxwell (correctly) uses the previous NDb and NDa in the stack to treat this as a liquid-to-glass transition
- Intersection of ray R1 at point X2 evaluates similarly to step 6 Snell's law (of the propagation diagram). This is a non-incident intersection and the ND is irrelevant. Maxwell (correctly) uses the previous NDa and NDo in the stack to treat this as a glass-to-air transition
Similarly the behavior of ray R2 is evaluates to air-->liquid**-->glass-->air (please see diagram for the "key" explanation of liquid**
I believe this diagram will give the most correct liquid+glass result.
This method was also confirmed with a real-life experiment as illustrated later on here:viewtopic.php?p=27866&highlight=preliminary+results#27866viewtopic.php?p=27837&highlight=uploaded+experiment+scene#27837