[Plugin] RayTrace & RaySpray

AdamB

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...

thomthom

@adamb said:

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.

hmm... a plugins to analyse the model from the current viewport and highlight the ones with many sub-pixel polygons... or is there one out there already?

ken

OK, I can visualize it now, the TV detective pulls out his laptop, fires up Sketchup and the ray trace plugin, and determine the bullets fight path, and solves another crime, all thanks to TIG and his plugin.

Ken

honoluludesktop

@adamb said:

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!

Sounds like I got it backwards

How about a render program that lets the user adjust select components (like keyboards in a large office) to reduce render times?

Didier Bur

Cool plugin TIG !
I'll surely use it to explain to my students how light bounces when hiting objects and so on
I cannot see the usual red-green-black-blue-cyan colored dots when snapping points for postionning the start and end points. Is this normal ?

TIG

@didier bur said:

Cool plugin TIG !
I'll surely use it to explain to my students how light bounces when hitting objects and so on
I cannot see the usual red-green-black-blue-cyan colored dots when snapping points for postioning the start and end points. Is this normal ?

I have probably not set 'inferencing' properly in the tool code !
I did it in a rush...
I'll look at it..........

Didier Bur

I give you 1 hour to correct the problem. And please DON'T GO TO SLEEP. HEAR ME ?

ken

TIG

Thanks for a fun plugin. I know other will need this, and I know sometime in the future I will be able to find a good use for this plugin.

On a side note, my version just keep bouncing the ole rays until it doesn't hit anything. I was playing with it in a box. Selecting the "NO" bottom does not stop the rays.

Just passing this on. If I am the only one with this problem, I can live with it.

Again, thanks for plugin. Can't wait until I find some usual project for this plugin.

Ken

TIG

Here's v1.2 http://forums.sketchucation.com/viewtopic.php?p=235227#p235227
The bouncing now stops on 'No' - stupid typo
Inferencing improved.
[Sorry it took so long - but I do have to eat etc... ]