Really slow render for animation

[NormAndTheGang]

Hi everyone,

We're working on an animation with Corona 2.0 and 3dsmax.
At 1920x1080, most of our scenes takes between 1-2 hours to render on our renderfarm (to get to a noise level of 2.0) but we have a scene that takes 13 hours per frame.

I've tried to remove any unused geometry, collapse railclones, simplify some materials but it still is very slow.

We're lighting the scene with a Corona sun and Sky and some Corona lights.

I looked at the Corona tutorial of Common mistakes but it didn't really help...

What do you typically look at when trying to debug a Corona scene?

I archived the scene and saved it here if you have any time to have a quick look.
http://www.mediafire.com/file/zq441t76czhi79g/Anim_INT-Lobby_06.zip/file

Thanks in advance for your help!

Chris

[maru]

Thanks for sending the scene. We will take a look at it and what can be optimized in it. There are different kinds of slowdowns/noise, so first we need to find out what we are dealing with.
Some helpdesk guides which may be useful:
https://coronarenderer.freshdesk.com/support/solutions/articles/5000501983
https://coronarenderer.freshdesk.com/support/solutions/articles/5000599619
(/local/Anim_INT)

[Bzuco]

Just quick look:

There are no portals in windows, camera is behind glass window, no camera is assigned in forest pack carpet (waste of polygons which are not visible), new light solver should be enabled in render settings if you are using not some but plenty of lights :) .

EDIT1: also backplates with corona light material outside did not help you in terms of reality and speed. Corona sun angle is useless in your example.

[sprayer]

also there is vray material near the coronaLightMTL in lamp, i think it will produce noise as corona material without rayswitch

[NormAndTheGang]

Hi guys,

thanks so much for your suggestions we'll have a look at them and try to improve the speed of the scene.
We'll let you know how it goes but I think removing all the Vray things in the scenes will most likely help.

Thanks,

Chris

[maru]

Sorry for the delay. I've just quickly checked the scene, and it seems it might need some serious optimizations. The camera being placed behind glass may be causing some troubles, especially that there is a bump map applied to that glass. But that's just one thing. Another is for example the ceiling lights. There is an invisible rectangular light, which emits light, and that's perfectly fine, but right above it there is a tiny spherical light, which also emits light, and that light is reflected from the reflective casing that the light is placed in. That's totally wrong. I would advise replacing those small lights with a geometry painted with CoronaLightMtl with "emit light" disabled, or CoronaMtl with self-illumination enabled. Other than that, you can try lowering Max Sample Intensity in the Performance tab (to 10?), and enabling the New light solver should probably help too.