Laser scanning effect

Archived Forums Questions & Answers
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I want to create a laser scanning effect similar to this;


I don’t want it to have a waving effect like that one; just a simple flat plane that scans the room. The tricky part is that I want it to outline every mesh object it intersects. Is there a simple way to do this for mobile?

Several possibilities - I'd try casting a series of raycasts, using a [Line Renderer][1] to display the beam itself, and perhaps creating a glowing object or particle effect to highlight any points it hits. [1]: http://docs.unity3d.com/ScriptReference/LineRenderer.html

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Thanks! I don't think I can use the linerenderer because it billboards to the camera. I need the beam to be fixed from the camera. Raycasting sounds like a good idea to detect the objects though. How would I emit particles from the raycast hit point?

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How many rays? What do you mean by 'outline'? What platform?

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I'm not sure how many rays I'd need to achieve the desired effect. This picture shows what I'm trying to do a bit better: http://capturelifethroughthelens.com/wp-content/uploads/2011/10/DSC_0541.jpg The 'outline' I'm talking about is actually the hard green line you see drawn on the people and background objects. Inside the plane I just want animating clouds type of effect. This is for Androud/iOS so it needs to be cheap if possible.

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My first though for the ray is to build quads for each ray and uv map in different rays from a texture. The quads would fan out to give the beam look. I started to write some demonstration code to see how it looked, but I'm out of time at my desktop for writing code at the moment.

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2 Answers

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I would use a projector with a cookie constraining it to a line.

A light with soft shadows would do a good job to.

As for the in air glow perhaps you should try and use a asset like Unity3D Extension: Volumetric Light Beam Kit - YouTube

Thanks, I'll give the projector a shot today. The only issue I'm seeing is that a lot of my environment objects share textures, so if the projector is mapping the texture directly to UV it's going to make for some uglyness. We'll see..

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You may want to add a few fanning raycasts that drive line renderers, that way the in air beams would also be occluded by the props in the scene.

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A particle effect with world collision enabled and a submitter on collision?

Now that I write that down it could be rather expensive.

Yeah I had that thought as well. I think I could make it work, but for mobile it's probably too much. How would I cast multiple rays in an arcing pattern? IE - ray1 = 0deg, ray2 = 10deg, etc?

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