How To Achieve This Effect

Community Forums/General Help/How To Achieve This Effect

Gabriel (Posted 2009) [#1]

This could go in any one of about four different forums. I'm just basically after methods of getting this effect. I don't really mind if they're for rendering in 3dsMax or for realtime in Blitz3D or realtime in anything else. It's not for a game or anything. I just have a hankering to play with the effect a bit. I'm not too fussed about the actual projection. I can do projective texturing in realtime (and probably in 3dsMax) but it's the whole streaky beam effect that goes with it that I'm not so sure about. It's a little bit like radial blur but I don't think that would work at such an oblique angle and I think it would be very expensive to get such a long beam that way anyway. It's a bit like God-rays too, but the same caveats apply as with radial blur, I suspect. Just curious if anyone has any ideas.

Ked (Posted 2009) [#2]

I don't think I see an "effect"...

Brucey (Posted 2009) [#3]

You need to look at the image proper : <http://tvtropes.org/pmwiki/pub/images/bat-signal.jpg> That site has disabled deep linking.

Ked (Posted 2009) [#4]

Ah. :) I see it now.

GfK (Posted 2009) [#5]

What I'd do is get a batman logo and sellotape it to a torch. Then wait for a really foggy nigh....... oh, I see what you mean. You can probably do it in 3DS Max with a volumetric spotlight with raytraced shadows. Otherwise it should be possible in Blitz3D by applying a 'god ray' texture of sorts to a quad and manipulating the vertices so its stretched to a single point. I don't have 3DS Max or Blitz3D on here so I can't test either of the above, just bouncing ideas.

Gabriel (Posted 2009) [#6]

Ah, volumetric spotlight, that sounds like the ticket for a rendered version. The god-ray texture and manipulating the vertices sounds like it might work. I'm not great with textures and sprites for special effects, but I'll have a play with that and see what I can come up with. It may take a fair bit of trial and error, but it does sound like it ought to be possible to get it looking pretty decent. Thanks for the suggestions.

Matty (Posted 2009) [#7]

I think Fredborg had something like that in the code archives - textured spotlight I think it was.

Kryzon (Posted 2009) [#8]

But Matty, that's for the projection of the logo. I think Gabe meant the volumetric-light beams. If you play Half Life 2, they simulate volumetric light in a really simple way with 2 quads, if I'm not mistaken (it's on a tunnel on one of the hover boat episodes, if I'm not mistaken). One for the side view, other for the front view. Then you interpolate the alpha of those two based on the position of the camera relative to the spotlight, in a way that if you are entirely on the side of the spotlight, you get something like the picture you posted. If you are in front of it, you get a big, blurry circle.

big10p (Posted 2009) [#9]

Jfk (I think) did a volumetric-light-beams-through-a-window type demo. In the code archives, I think.