Visible Light Paths?

[Barry Hayden]

How do you make a Visible Light Path?

For example, I would like to render a projector shooting an image onto a screen.

How do I show a visible beam of light from the projector to the screen?

[Albert D Hart]

My original reply only applied to nXt for SketchUp.

You can read it here:

http://forum.irendernxt.com/forum/topics/visible-light-paths

[Barry Hayden]

I am using Accurender NXT for Autocad version:1.0.329

Where is the "Lighting Wizard" tab?

[Albert D Hart]

Oops - Sorry - I didn't ready your original post properly. That beam wizard only works with SketchUp.

But the rendering properties will work in AutoCAD. You have to create your own geometry and material settings.

We are creating concentric cones with a translucent material, and adding bump maps to them for effect. The cones are all near the edge of the light beam from the spot light.

We create multiple cones - very close to the same size

Ant set the spot light beam and field angle to shine only inside of the cones.

Another way to do this is with volumetric fog:

http://wiki.mcneel.com/accurender/nxt/documentation/beyond/volumetr...

[Kevin Lockwood]

On a small scale using Path Tracer and Fog

[Peter Milner]

This is one I did 3 years ago when fog was first introduced.

[Maciej]

Peter, that's exactly what I've tried to achieve. Perfect stained glass window.

Wouldn't you mind to share your  know-how about this effect?

[Peter Milner]

The stained glass window was modeled as a region and tagged as "Thin". The decal was applied with the following settings (the masking was to exclude the black from the transparency so that it would cast shadows:

Here are the fog settings:

I'll see if I can strip the model down to a size where I can upload it.

[Peter Milner]

Having said that, I'm just re-running the render again and it doesn't seem to exhibit the same light beams. The original was rendered in January 2012 and I seem to remember some setting to do with particle size and density.

[Roy Hirshkowitz]

Path tracer, right?  This is still on the todo list for the Hybrid.  Turn the fog way up (Scattering) to make sure it's still working.

[Peter Milner]

Yes it's still working. I just turned the scattering up to 0.1 and the result is very similar to the original.

[Peter Milner]

Here it is after 2000 passes.

[Aguinaldo Marinho]

Se eu quiser usar Spot, jogando de baixo para cima, como faço?

Não achei configurações para fazer o Spot lançar luzes estreitas e longas através do nevoeiro!