Flicker free animation - changing light levels

[ABK]

Hi Everyone,

 

I'm rendering an animation of a scene that is lit by lights that change colour and intensity throughout the animation.

 

Do you know what would be the best GI settings to use to ensure that I don't get any flickering?

 

Cheers,

Antony

[Tom Sproule]

Hi Antony,

 

For GI you would need Light Cache and set it at about 1500 to 2000 and then use Brute Force.

 

When guys do animations in the office I have them get an animation of a frame down to about 15 minutes.

 

I do it by increasing the noise threshold and lowering the subdivs in the 'bucket image sampler.' The subdivs sometimes as low as 10 and the noise threshold as high as 0.03.

 

This creates a hell of a noisy render sometimes, but then we put on the VRay Denoiser element in the Render Elements and then change the preset to strong.

 

That normally gives us a pretty good animation which renders quickly.

 

To handle any remaining flickering you'd need to lower the noise threshold and increase the subdivs - which will increase rendering time and depends on how much you can spend on rendering.

 

Due to the fact the denoiser can make the image slightly blurry it's a good idea to add on an AO.

 

Here is a tutorial I did on how to do that:

 

 

You basically add a VrayExtraTex render element and then in the texture slot put a vray dirt map - set it at about 100mm.

 

Add that in post and your details come back.

 

That's a simple breakdown of how to do it.

 

Like I say, if you are still unhappy with the flickering then you'll need to look at lowering the noise threshold down to around 0.005 and increasing the max subdivs. But that will increase render time and cost.

 

 

 

Best,

 

Tom

[James Vella]

I wrote a short tutorial on how to produce flicker free vray renders awhile ago before the vray denoiser was introduced - however this was producing very quick renders very clean. Feel free to test out a couple of frames and if you like it then it will work for your animation:

 

http://jamesvella.blogspot.com/p/tutorial-simple-vray-walkthrough.html

[Francisco Penaloza]

Regarding that tutorial from James Vella, in this case, that old method won't work because you are baking the lighting on the objects.

To the original question from Anthony, if you are using the latest V-Ray 3.x then just setup your Light cache to 2000 or so and leave brute force as a first bounce, do not pre-save light cache. Just let it render each frame. You can also use brute force in both bounces but this will produce more noise but that also depends on your scene setup.

 

Using Denoiser is a big help as mentioned by Tom S.

 

Also if you know your way around After Effects or similar you could use the light select pass and render your animation with statics lights and then animate their intensities in post.

For this, you will have to render other passes such, Diffuse, Raw Lighting, Raw GI, Reflection, Refraction, Secular and such, but this way you can have full control of your lighting effects if your clients get picky at last minute.

 

Now if the animation is just a typical Sun time lapse, then the first method will work just fine.

Best luck!.

[James Vella]

Regarding that tutorial from James Vella, in this case, that old method won't work because you are baking the lighting on the objects.

To the original question from Anthony, if you are using the latest V-Ray 3.x then just setup your Light cache to 2000 or so and leave brute force as a first bounce, do not pre-save light cache. Just let it render each frame. You can also use brute force in both bounces but this will produce more noise but that also depends on your scene setup.

 

Using Denoiser is a big help as mentioned by Tom S.

 

Also if you know your way around After Effects or similar you could use the light select pass and render your animation with statics lights and then animate their intensities in post.

For this, you will have to render other passes such, Diffuse, Raw Lighting, Raw GI, Reflection, Refraction, Secular and such, but this way you can have full control of your lighting effects if your clients get picky at last minute.

 

Now if the animation is just a typical Sun time lapse, then the first method will work just fine.

Best luck!.

 

This is correct, if any object that is moving other than the lights than go with brute force as Francisco advised