Hi, has anybody made a cinema projector light beam before?
Im using a light and rays as a base but i need to make it look more realistic ie take on the colour and changes of the projection and coming from behind the camera as if its a pov of the projector.
It’s been a couple years now, but I have done this exact thing. It was pretty fiddly and slow to render, but it worked. The trick was that the light/rays combo breaks if they get too far outside the frame of your Action. I seem to remember having to build a super-sized action node with the light in frame, with my rays and source image/gobo attached, and then comp/scale/repo it downstream.
I also remember having to crank my light and sample values extremely high to get the ray definition I wanted. It was pretty frustrating! But quite satisfying when I finally got something that worked. The key in our case was that the rays had to sync believably with the images, and the images were likely to change at the last minute, so I couldn’t go rebuilding the whole thing every time we got a revision.
Anyhoo, the end result is below. Let me know if that helps at all, I don’t have access to the setup, but I’d be happy to boot up flame and see if I can rebuild it if you’d like something clarified.
Thanks for that, its look great. Trying, how did you get it to react with the images?
I think I put a surface in front of my light, basically a gobo, and then let the rays take it from there. @La_Flame did a nice video YEARS ago that illustrates the basic technique. Check the 2nd half where he gets into the stained glass look.
Also, playing around with it for a minute here, the secret to getting the light to throw rays based on the image when it’s pointed away from camera seems to be to parent the surface to the light.
From there you have to get the image very close to the light and fart around with your parameters until you get something you like.
I remember more of this now, and as I said before, it was quite fiddly and frustrating, and once I got it working well enough, I pretty much left it alone.
Thank you for taking the time to do that
Well I hope it was helpful, let us know how it works out!
Thanks for sharing that. I have to do this soon on a new project.
Good trick to know. Thanks @kirk
For anyone still checking this thread, I just had a play with it again and was beginning to experience a sort of despair because I couldn’t get it to work for me. I was convinced that either something broke in flame or I’d somehow regressed in skill since last year (still a possibility).
One thing is you can get it working with the light pointed towards camera, but if you orbit around, or rotate your light, or change pretty much anything, aspect wise, it screws it all up.
So the OTHER secret (and I have no idea why) to getting volumetric rays to work when the light is aimed AWAY from camera, is, apparently, to turn f’ing Z-Buffer off.
Otherwise, most of Grant’s stained glass tutorial still applies: Use Object Rays and play around with the intensity of those, plus the global intensity and spread of the rays, plus the intensity and spread of your light, PLUS the scale and position of your gobo until you find something plausible/that you like, then pray your camera doesn’t have to animate (or if it does, pray you can pre-render your rays).
And keep in mind that none of this really works if the light is outside the raster of your action setup, which is fun.
Honestly, if I were going to do this again, I’d probably do it in Cinema/Arnold. Way less fiddly.
