Animation

[m2410]

Hi,

I've been using corona a lot recently and find it great, produces really nice interior images which have a more realistic feel than vray

I'm trying to render an animation of an interior scene I've done. It's fairly short/slow paths. There are moving light materials in the scene and a door opens but apart from that there is nothing complicated

I am having a real issue with noise. It seems to be something to do with my internal lights and glass. Are there certain refraction settings I need to apply to the glass for animation or anything I should do to the lights?

I have tried UHD load and append every 10 frames and from scratch every frame, which is the best option?

Really appreciated any help

thanks,

Marc

[maru]

Hi,

The lights - can you post some pictures of them? What kind of lights are these? Maybe you are confusing LightMtl with self illumination? Here is a guide:
https://coronarenderer.freshdesk.com/support/solutions/articles/5000515603

Glass - if the light sources are strong, you probably see reflective caustics. You can reduce them by reducing Max sample intensity ( https://coronarenderer.freshdesk.com/support/solutions/articles/5000515636 ) - but this will have impact on whole your scene lighting, or disable them by nesting your glass material in a RaySwitch material and disabling GI for it (leaving its GI slot empty).

UHD Cache - if there isn't a lot of movement, you should get away with creating the cache every X frames with load+append.

Let me know if this is helpful. Any pictures/examples would be great.

[m2410]

Thanks For getting back to me so quickly. The interiors are lit with corona lights. Sorry I don't think I explained it very well! I've got a tv and a fire in some of the rooms so I have an animated texture on a light material for those

I've attached a screengrab of an exterior part of the animation. The noise on the exterior looks like it's cleaned up ok but when you start seeing through the glass and where the internal lights are illuminating the exterior its very noisy (render time was about 45 mins per frame 30 passes)

I've also attached a section of an interior this was taking about 1hr 10 mins perframe with 30 passes and is still noisy..was hoping to get render time to about 40mins

Thanks,

Marc

[yagi]

1) hi  m2410...  glad to here you speak up coz im having the same problem at the moment with my night scenes in some projects with corona lights on the inside and a few light mtl on the outside but havent resolved the problem yet so ive been avoiding night time renders.

2) i hope Maru or any other pro has a quick answer as to what we may not be doing right...

3) im also with an issue where the scene is stuck on "parsing the scene" and if it makes it pass this sage then it gets stuck at "building ac structure".is there a link that can better explain what these 2 quotes mean so i mite know what the possible problem is
    ive also noticed that when i region select a part of the image it takes about 10-15 mins to pass this stages and start rendering but when i set it to view it takes over an hour and i have to cancel the process... it could even take over 5-10mins to cancel fully thereby allowing me to save any image created in beauty pass.
* my system specs are 3.4 ghz core i.7, 12gb ram, 500gig hd, ati radeon 6series etc.. if the specs is the problem pls someone let me know.
* if theres any other information i need to post pls let me know, including an image. thanks

oh n sorry for taking the opportunity to discuss my own issues in your own post :)

[m2410]

Hi Yagi,

No problem we're loving using corona, I think Marus' advice on the MSI number works well. Here's a quick region render I did of the same scene. neither have photoshop or noise reduction applied. The one attached has an MSI value of 2 rather than the default 20 and it seems to have cleaned up much better. both did 30 passes.

Ive only had that issue you've had with parsing the scene etc on really big scenes, corona proxies or x-refing objects in has helped. 

[Noah45]

The MSI adjustment looks much better, how much longer render time for 30 passes?

[yagi]

hmm.... i'll try it out. it seems increasing GI vs AA a bit would help too?. thanks for the help links@maru but i wish i understood how "parsing the scene" and "building Acc structure" works or its meaning in corona once i hit the render button. im particular about these two stages because i have a feeling it would better help me know the proper way to work with my scenes : peharps the scene file is too heavy(as ive noticed it takes longer parsing the scene on uhd cache when its over 150 - 300 mb), maybe there are too many polygons, maybe i need to proxy more objects, maybe i need to do more instancing than copying, maybe my lights in the scene are too many or using inaccurate light parameters, or maybe one material or all suck in my scene? ...i need to understand these things more to help workflow. i even heard you shouldn't import proxies from previous scenes that its best to start creating new proxies afresh in your scenes, true?.

[maru]

About the better-looking shot with msi@2 - great, but if you set msi to 2, then you basically kill all GI, if you are ok with the result - then ok, but this introduces HEAVY bias. I think there must be some wrong setup in that scene. Maybe those ceiling lamps - are they small Corona lights behind glass? Are you using IES lights? It would be great if you could isolate a part of this scene while still maintaining the problem with noise, and send it over to our support: https://coronarenderer.freshdesk.com/support/tickets/new

@Yagi - this definitely shouldn't be happening and sounds like this:
https://coronarenderer.freshdesk.com/support/solutions/articles/5000678431
Please check if 3dsmax or some related process is on the FTH log.

[m2410]

Thanks Maru, it's still noisy at the end of the animation. I might try that glass thing you mentioned about the GI if that doesn't work I'll send part of the scene. I've done the Albedo pass and everything looks fine on there so I'm not sure what is happening. it is a large scene with lots of objects..maybe it just needs more passes but I can't really afford to have it doing more than 40 mins a frame. I did a still twice the size and let that run for 10 hours....that worked well!

The lights are small corona lights behind glass. should I try moving them in front of the glass? they are corona lights with IES

thanks,

Marc

[maru]

It could cause some problems (caustics I guess). I am attaching a scheme of what I think would be the most efficient solution, where:
A = flat circle with Corona material with self illumination enabled, or light mtl with "emit light" unchecked, strong enough to be visible directly/in refractions/reflections, but weak enough not to cast light/noise
B = glass
C = light with IES, or standard Max photometric light with IES - Corona lights sometimes get crazy with IES
Btw, which version of Corona are you using?

Also, this could help:
https://coronarenderer.freshdesk.com/support/solutions/articles/5000516731

If it's an animation, I would suggest reducing GIvsAA - this would decrease per-pass quality of GI, but would increase AA quality in given rendering time. Why? Because it is easier to remove noise in post production, then to improve appearance of poor AA sampling (for example on edges). And 30 passes, which you mentioned earlier, may not be enough.

[m2410]

Thanks Maru,

I'll give that a go and also add a rayswitch material to my window glass