Animated light to mimic a Fire?

V-Ray V-Ray Common Tutorials, Tips & Tricks
1

Hi guys,

Could some one suggest the best way to produce this effect? I have a scene light with a dome light
and hdri but the backplate has a fire off camera that is creating some flickering in the shot and my character needs
to have the same lighting on it!

Thanks

2

Try tracking a point on the plate that visibly has the effect of the flickering fire on it. Then attach a crop to that tracker that includes a decent number of pixels (maybe 15x15) and blur the result which will average the pixel values. Make it grayscale and output an image sequence you can then use in Maya. Connect the image sequence to a set range node and do some test renders to figure out what the brightest and dimmest values of the fire flicker should be. Connect the output of that to the intensity multiplier of your light.

Tim J

3

Seraphs method is probably better but here is what I would do: just put the flame of the fire in your plate onto a geo plane make it invisible to camera and use gi to emit lighting from it, the timing of the fire will be exactly as it is in your image sequence. The downside of course is that you need to use gi and probably brute force gi to get it to look good but its quick and easy to set it up.

4

Me, i connect directly the plate into the color of the light.
Same color, same intensity.

5

Thanks guys, Will give the methods a try and see what I get!
Thanks for the replies!!

6

Maybe I misunderstood, but I thought the actual fire in this case was out of frame and therefore couldn’t be used directly. If the fire is in frame then crop a sequence of it and use that instead.

7

another alternative, if you wish to experiment would be to render a constant light from your fire light source as a raw light element and animate it flicker in comp, this will give you the ultimate control vs time.

8

Thanks guys, got it sorted in the end, the fire is out of shot so i just
used a vray light with a warm temp then rendered that out in a different pass and comp is going to handle it
shame though would of liked to test it out in maya with VR but i would have been a bit hard match the back place correctly

Thanks for all your help though