Laser beam effect...

[ch_ro]

I'm currently faking laser beams in Rhino by applying an emissive material to a rectangular "ribbon" and then putting a gradient in the transparency channel aligned in the U direction to simulate falloff. The only problem is the ribbon has to point toward the camera properly for it to look convincing, so any time I move the camera I need to tweak the ribbon orientation. What I'm looking for is a proper way to do this (without fog or environmental scatter because I feel that's overkill) with a cylinder where "light" fades off radially, but I don't think Vray 5 and Rhino 7 can do this? Thoughts?

[Jonish]

What about giving the cylinder emissive material + playing with Lens effects in VFB?

[nikolay.bakalov]

Hi,

totally not pretending to have any expertise on 3D modelling, but have in mind that cylinders with very small diameter (lasers) do not produce good falloff. Even with high rate of discretization. Currently this is the problem with Rhino linear lights - long thin "sticks" give off light in bands. Kind of. Effect is visible in both Cycles and V-Ray. I was told that using two rectangular lights in back-to-back formation as a "ribbon" instead shall be the preferred solution.

Don't believe me, though - try it out

[ch_ro]

Yes, emissive material on a ribbon (or cylinder) is what I've been doing, but in either case the texture has to be oriented correctly for the effect to look good. Even with this slight inconvenience, it sounds like this is the best approach, so I will continue with this method. By the way, is there a way to combine independent gradients in the ribbon approach? What I mean is putting a gradient in the U direction is easy to fake falloff at the edge, but what if I wanted to fade the beginning or the end of the beam - i.e., a gradient in the V direction that combines with the one already in the U direction. Is this possible?

[konstantin_chaos]

You can mix 2 gradients using one of the Mix options in V-Ray:

[konstantin_chaos]

And by the way you should consider this option:

It is a common hack used in games.
The render performance is not great but it looks good.
Here's the RH file - Laser_01.zip