Changes in brightness rendering a bongo animation w/flamingo


I am fairly new to flamingo, I hope this is an easy fix, I am under time pressures.

I created an animation with bongo, some stuff dropping in from the top of the frame into an assembly. Rendering in 720p, 50 passes per frame, using a groundplane with a flamingo brushed aluminum material applied to it. I have the setting reflect visible background checked, using a solid black background. Also using the standard light, set on studio lighting, with no extra lighting added to the scene.

The machine is a HP Z840, with a quadro 5200 graphics card.

The animation took about 20 hours to render, and to my dismay, at seemingly random intervals a frame appears in which the overall brightness is quite different than the others, much brighter, leading to unusable results.There are slight differences in the way flat surfaces are lit as well, they sort of gently flicker. Also, I tried to re-render the offending frames, and again, to my dismay, it seems that every time I quit rhino and re-open the file, I get slightly different results, enough to be noticeable.

Does anyone have any suggestions of what I might be doing wrong?

I think you may need to render a single frame and lock the exposure of the Flamingo nXt render with the check box in the lighting adjustment section of the render window. Then render the animation after that… the locked exposure value should get used for each frame. I’m thinking the flicker is due to nXt getting a different tonemapping result from frame to frame. You can’t turn the tonemapping off but you can lock the exposure.

Any luck? I’d do a small test so you don’t waste more time.

@scottd please jump in if you think I’m off on this one.

Thank you for the reply. Locking the exposure helped tremendously. Still a bit of flickering on large flat surfaces, but when I pointed it out to my boss he couldn’t even see what I was talking about. Thank you kindly for saving the day.