B How would someone see light from something like a flashlight in a tunnel?

[AI_Messiah]

TL;DR Summary

Light Refraction

What I mean is that how would someone see light from something like a flashlight in a tunnel? The idea of light rebounding like a ball against a wall I do understand. What I would like to apply this to is graphics programming. the objects that I would simulate this for are puddles on the floor and copper connectors. The puddles are quite thin of course. I thought since I would ask for a physics answer I would not go to a graphics forum.

 

[DaveC426913]

Where do puddles factor in?

 

[sophiecentaur]

Where do puddles factor in?

Diffuse and specular reflections need different treatment.

There are many ray tracing apps that can do this for you.

 

[DaveC426913]

Diffuse and specular reflections need different treatment.

There are many ray tracing apps that can do this for you.

Sure, I'm just trying to figure out what the OP is trying to achieve - or even ask. What does a flashlight in a tunnel have to do with specular reflections for example?

And what do they mean by "I would simulate this"? Are they writing their own rendering engine? If not, why these questions?

We need clarity.

 

[sophiecentaur]

What does a flashlight in a tunnel have to do with specular reflections for example?

A tunnel with a matt black wall would be the most trivial case with only light directly from the flashlight reaching the observer. Very reflective walls would produce many images of the lamp (as in a kaleidoscope) due to the specular reflections. A mixture of the two could be well worth simulating if you wanted an appearance of reality in a game or demo.

 

[Drakkith]

I thought since I would ask for a physics answer I would not go to a graphics forum.

Honestly, I would recommend going to a graphics forum (or programming forum), as graphical ray tracing is a very specialized process that is handled somewhat differently than you might expect. Namely that rays are often calculated as being emitted from the camera and traveling to various parts of the scene, which is reverse from the way that real light works.

 

[sophiecentaur]

Honestly, I would recommend going to a graphics forum

Agreed. A graphics forum would help you to select the appropriate bits of Physics to get the job done. PF could flood you with stuff that's not needed for your requirements.