Vray light. Anyway to change size proportion when using high directional values to create laser type lights?

[stevesideas]

Is this possible? No matter what length/width I use on a light it always ends up as a square at the end of the directional volumetrics.

[vladimir_krastev]

Hi, thanks for posting. Please check the example below. I have a VRayLight with directional value of 1, a rectangular proportion and a VRayEnvironmentFog. Is this what you are after?

[stevesideas]

Hi there. That makes total sense but if you try to have a thin laser type light from a small source...ie, a length of 2cm and width of 0.5cm for example and then change the directional to something like 0.8 the light will not stay thin in proportion. It will expand out and not remain flat...like a laser light...

If you imagine the below light starts from a very small point and only expands in length but not in height. Is this possible?

[vladimir_krastev]

HI, the laser emits parallel light beams. This means a directional value of 1. Anything other than 1 is not a laser but a regular projector.

If you imagine the below light starts from a very small point and only expands in length but not in height. Is this possible?

Not directly available in VRayLight. Let me think of a way to accomplish this. There could be information about such effect on the forum already.

[stevesideas]

The standard 3dsmax lights can do this in terms of being able to change aspect ratio. Obviously they are not physically correct. It would be great to have this ability as I often do visuals that require this kind of light.

[Joelaff]

What do you mean by change aspect ratio? Can you not just change the radius of a Disc VRayLight (directional 1.0) ? Or the length and width of a Plane VRayLight (also directional 1.0) ?

Or does that not do what you need?

Basically, with Directional set to 1.0 the VRayLight produces a straight beam, like a light saber (with no taper) or laser.

For laser, though I have sometimes found a simple self illuminated cylinder to do the trick, but it depends on the shot.

[zoranm]

I used to do that long time ago by making a black mask in front of Sun. Set size=0 to have sharp shadows
Z.

[flat]

Don't forget that V-Ray3dsMax can use 3dsMax's standard Spotlight.

Attached max2021 scene