Rendering a laser beam


#1

I’m new to Rhino, and rendering in general.

My goal is to render a red/green laser beam hitting a glass-air interface, resulting in a diffuse scattering. I don’t care about the transmitted beam — what I’m looking for is a diffuse elliptical “spot”.

The effect I want is similar to a laser pointer hitting a pane of frosted glass, except that the glass itself is clear. I want the laser itself and the surface it touches to glow like a lightsaber.

It’s just a laser pointer bouncing off a window very obliquely.

TWO ISSUES:

  1. Getting a realistic laser beam is proving challenging. I have an X% transparent green beam rendered as a very fine cylinder and casting no shadow, but this is a bit average.

  2. Getting a surface to be “emissive” such that a translucent object held close to it will be illuminated brightly, but objects further away will scatter less light.

Anyone have any pointers on how to deal with this, or a link to someplace where it is discussed?

Cheers!


#2

What are you using to render? If using the basic built-in one, it’s not really capable.
Brazil should be able to brute-force quasi-realistically do this using photons(some trickery might be required for the visible beam) or you can ‘fake’ it using various methods.


#3

I’m using Rhino’s basic Toucan renderer on the Mac development version, but have access to KeyShot and SolidWorks through my school so if you have experience with these alternatives I would welcome any suggestions. Also Blender and Kerkythea, obviously, but I have to stress again that I have some nice CAD models but little or no experience in rendering.

Thanks!


#4

From your list of renderers, i would suggest to use Blenders internal renderer. Using render nodes and postprocessing it should be possible to fake the diffuse scattering or maybe dispersion effects in relative short time. You´ll find most information online if you google for “Blender laser beam render”, or see the scene attached here.

on the other side, if you have enough time to experiment with a free physically based and unbiased rendering engine, try to do it via LuxRender which can be driven through Blender as well. Examples are located in the Luxrender Forum.

c.


#5

Thank you so much for your response, I was playing with Blender today to try and reproduce some of the effects shown in the videos and websites you linked to. Unfortunately for me I’m looking for a couple of things that might be easy to “fake” by a pro (despite being bloody tough physically), but are a bit beyond these links.

It’s proving a little tricky for me to get the effect I’m looking for, so I figured it might be useful for me to upload an approximate version of what I’m trying to get to.

To summarise the tricky bits: I want a laser (green, red… whatever) striking the top glass surface and producing a soft glow that drops off away from the interface. Then I want to be able to have a ball that looks like it is scattering the glow. Ideally the scattering will be “either side” of the ball, with the brightness dependent (manually or by the way the lighting is set) on the elevation of the ball above the interface where the laser strikes.

I feel like this ought to be “straightforward”, so if someone has a quick and dirty solution for something that DOESN’T have to be photorealistic I would be really grateful.

It’s for a presentation — I’m sick of having boring slides, so once I have a way of doing this for a simple case I’m looking forward to making pretty videos of a bunch of simple (and more-complex) scenarios to chat about during my talks.

Thanks again!

Basic Laser.3dm (598.3 KB)


#6

I should mention — I know this goal is relatively simple, and that it is probably possible to achieve it to varying degrees of success with most common rendering tools.

I am being half-lazy. I am hoping someone who knows roughly what I need to do will point me at the right tool to do it quickly, because I don’t want to spend a month figuring out how to do photorealistic rendering and then realise I haven’t got enough time to do the work I need to present using the pretty figure/video in the first place.

Grumble grumble.


#7

i don’t know… that’s going to be tougher than you’re making it out to be.

for instance, the air is going to have to have ‘something’ in it in order for the laser to show up and produce the glow you’re after…

my renderer (indigo) has a Turbidity control (basically- haze) which will moreORless control the amount of dust/water in the air and give something for the laser to become visible but I’m not enough of a render nerd to give exact advise… it’d be more of a trial&error thing.

idk, you’re not going to find these types of controls in rhino-for-mac’s built in renderer… you might be more likely to get the info you seek at a dedicated rendering forum.

if you want to fake it or get it sorta close, you’re probably better off just doing it in an image editor.


#8

It’s for illustrative purposes, so yes I’m happy to just “fake it”; but I also have it in my head that I’ll be able to pan-in from a birdseye view of a static piece of equipment which contains the object included in the Basic Laser.3dm file.

Looks like this might be a tougher ask than I first imagined :frowning:


#9

Have a look here and here for video tutorials on how to get something basic which can be used for animation.

c.