[Plugin] RayTrace & RaySpray

[TIG]

This is in response to recent requests for an early-stage acoustic reflected-ray design tool...
[works for light and balls too]
DOWNLOAD THIS FILE
raytrace.rb

(c) TIG 2010

raytrace.rb

Place the script in the Plugins Folder.

Usage:
'RayTrace'
Type raytrace in the Ruby Console or
pick 'RayTrace' off the Plugins Menu.
Follow the prompts:
Pick the Start Point of the 'Ray Trace'.
A magenta guide-line shows the possible 'Ray' path.
Pick the End point of the 'Ray' on any face.
A 'Ray' is drawn between the two picked points as a guide-line with
guide-points.
The reflected 'Ray' is then drawn - it extends until it hits a
face. If it hits something then a guide-point is drawn,
otherwise the reflected 'Ray' guide-line is drawn infinitely long.
If the 'Ray' has hit a face then a dialog asks if you want to
'Bounce the Ray': answer Yes to make the next part of the 'Ray'
or No to stop this 'Ray'.
If these is no hit then that 'Ray' set automatically ends.
The tool now repeats: to stop select another tool or press <Esc>.
The set of 'Rays' is grouped for ease of identification or later
deletion.
Clear Guide-points and Lines using third party-scripts or use
Edit > Delete Guides...

   'RaySpray'
   Type rayspray in the Ruby Console or 
   pick 'RaySpray' off the Plugins Menu.
   Follow the prompts:
   Pick the start point of the 'Ray Spray'.
   A dialog asks if you want to constrain the spray in X/Y/Z-planes 
   or 3D.
   It also asks for the angle of separation of each of the spray's 
   rays - default is 30 degrees - closely angled rays take more time 
   to do - 3D rays are obviously more intensive.
   The 'Ray' guide-lines and points are grouped, as in 'RayTrace' .      
   There is no 'bounce' option with this tool, but once it the 
   'Ray Spray' has been made a 'Ray Trace' can be done on any 
   desired Ray's points, with bounces as required...
   After one use the tool does NOT repeat, it needs reactivating...

Donations:
Are welcome [by PayPal], please use 'TIGdonations.htm' in the
../Plugins/TIGtools/ folder - or PM TIG for details...

Version:
1.0 20100324 First issue.
1.1 20100325 Possible Bounces added. Ray Spray added.
1.2 20100326 Bouncings now stops on 'No' ! Inferencing improved.

[watkins]

Dear TIG,

Tell me, do you ever sleep?

Bob

[pilou]

Does this accoustic ray takes the same way than the way for a ray tracer "light"?

[TIG]

@watkins said:

Dear TIG,
Tell me, do you ever sleep?
Bob

He asked; it seemed simple enough to do, so I did it...

[TIG]

@unknownuser said:

Does this accoustic ray takes the same way than the way for a ray tracer "light"?

The 'reflected angle' of a 'ray' off a face works the same for sound, light, balls etc etc...
So get working on your billiards game...

[TIG]

It only does one iteration [bounce] as that was what was asked for - if multiple 'bounces' are required it is quite possible to do it... although in a closed box shape it could go on forever !!!

[minguinhirigue]

This is really good ! Thanks.

It should be greater to have a dialog box with :
Iteration : number of reflexion of ray (bypass for infinite ray, and warning for more than 10 ?).
Number of ray : draw N initial rays from the focal point (warning for more than 30 ?).
Planar : option to constraint reflexions in a plan for early analysis of acoustic reflexion in the section of any room.

I guess I would be to busy to work on this, like dozen of other script that are waiting...

By the way, good job TIG, thanks.

[TIG]

Here's v1.1 http://forums.sketchucation.com/viewtopic.php?p=235227#p235227

It now has RayTrace AND RaySpray

RayTrace traces the picked ray from a start and incident point - it then allows 'bounces' to be made if there is a 'hit'...

RaySpray sprays rays out from a picked point, constrained in X/Y/Z-panes or full 3D with a desired angle of separation; there is only one reflection - no 'bounces', but RayTrace can be used over an earlier sprayed ray to 'bounce' individual ray-paths more if required...

All guide-lines/points are now grouped...

[mitcorb]

You didn't answer the sleep question

[solo]

@unknownuser said:

You didn't answer the sleep question

Because he is sleeping?

[Khai]

he's sleeping?
who let his Coffee IV run dry?

[mitcorb]

ok while he's away, let's debate the bouncing forever question shhh

[TIG]

I'm back !
Actually I was plumbing in a second bathroom !

The "bouncing forever problem" is avoided because you choose to do each additional bounce after the last reflection - unless when you are asked if you want a 'bounce' you are daft enough to keep pressing Y[es] a zillion times it will stop at he first N[o]... You only get a 'bounce' dialog Y/N if the ray has hit something after the last reflection anyway, otherwise it stops...

Any other ideas or even suggested uses welcome - I feel I've invented something that is looking for a use - e.g. Pilou's 'billiards' seems an outsider ???

[AdamB]

@unknownuser said:

Does this accoustic ray takes the same way than the way for a ray tracer "light"?

"Not really" is the answer. I looked into this when we were trying to design a new 3d audio system in a previous life.

So for light (MHz), the frequency is so high that diffraction / diffusion effects can be ignored. It moves in straight lines.

But for sounds (kHz) , edges/corners/gaps have huge effects. Hence you can hear somebody speaking when they're around a corner!

Moreover, the lower frequencies are going to spread around corners more than the higher frequencies components so what you hear will be different too. And just to make it even more complex, the substance of the building transmits sound - so if you're in the next room and listening to something, you may get high frequencies components coming out the door of one room into the door of the other while the low frequencies come through the wall.

[pilou]

Thx for precisions!

[honoluludesktop]

AdamB, That's right about sound, then again (I am guessing that) if you have a mirror, with a thick exposed glass edge, with refraction, the behavior of light too is not that simple.

Which brings to mind, the question of how much accuracy do we need? In one of my renderings, the biggest component is a pair of ladies shoes that I downloaded from Google. Nice touch in the rendering, but it was bigger then the architectural model itself. The other day someone posted a simple looking room with lots of computers, (maybe 50+) complaining about the size of his model. I'll bet that the keyboard keys were individually built with graphics, molded corners, etc. What did the renderer have to do to get that image out?

We need a program that will simplify mesh models of small things that are drawn with great care and accuracy. But guess that is off post:-), sorry.

[erikbernhart]

wow, good work TIG,
I was just wondering this morning if there is such a tool available in sketchup.
and it exists, created just one day ago!!.what's the coincidense
great tool for me as a student, who doesnt have such expensive software to do raytrace/spray modelling.

[AdamB]

@honoluludesktop said:

AdamB, That's right about sound, then again (I am guessing that) if you have a mirror, with a thick exposed glass edge, with refraction, the behavior of light too is not that simple.

But thats the point. The wavelength of visible light is so small compared to the thickness of the mirror, the interference between the bounce from the back of the mirror and front is effectively zero.

Unless you have very thin mirrors!

[OT: Few years back I lifted the hinged door off an old french clothes cupboard to do something. The door had a mirror on it and must have weighed 50-60Kg. I staggered over to the bed and dropped it on the bedcovers and noticed the mirror had tiny flecks of mercury oozing out. The whole mirror was constructed by sandwiching mercury between glass!]

[AdamB]

@honoluludesktop said:

We need a program that will simplify mesh models of small things that are drawn with great care and accuracy. But guess that is off post:-), sorry.

For many many years people have struggled with this "level-of-detail" issue. There has been some great work done by Hugues Hoppe etc but ultimately its difficult to get satisfactory results because the shapes have "meaning" to us that the computer program doing the reduction simply don't understand.

In some sense, we've got this all back to front. We should be describing our models with the minimum information and then refine that description to get more details. Certainly when you get to the point of having sub-pixel polygons, you have to question whether this is such a great representation.

[TIG]

This RayTrace tool etc IS a very basic tool - typically it's for use in placing elements, like acoustic reflectors in ceiling etc, at something like the correct angle to get the reflected sound to the right places.
You'd only use it in your early volumetric designs - once the design develop I'm sure specialist acoustic design tools will be used to fine-tune the details...