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gamedesign1
10-27-2015, 10:37 AM
Hi all

I am writing up an idea for an animated short film and I wanted to talk to you guys about some different ways of rendering scenes.
My scenes are going to be very detailed and using GI and rendering at 1080P.
I was wondering if it would be best to render the scenes as full scenes with full GI on everything or if it would be best to do some Baking to and then use some compositing to add it all together.

For example lets say I had a room with a character that moves around in it. I could one of the following:

1. I could setup the scene and render the whole thing using with it calculating GI for every frame which is obviously CPU intensive and will take a long time to render.

Or

2. I could bake the room without the character in it and do the camera move with baked lighting and then composite the character in later using a shadow catcher. Not sure how I would go about giving the character the right bounced light from the scene though with this method.


Any thoughts on this would be really appreciated. I hope it makes sense.

Scazzino
10-27-2015, 10:54 AM
Much depends on your goal. Baking and compositing can be rendered faster, especially if you need to do it more than once due to changes in the character animation. Rendering it all at once can result in better looking lighting, at the expense of render time. So it basically comes down to how much time you can give to rendering.

gamedesign1
10-27-2015, 11:34 AM
Much depends on your goal. Baking and compositing can be rendered faster, especially if you need to do it more than once due to changes in the character animation. Rendering it all at once can result in better looking lighting, at the expense of render time. So it basically comes down to how much time you can give to rendering.

Yeah totally, thanks

Scazzino
10-27-2015, 11:37 AM
The best way to answer that question is to run some tests. Render a 1 second test with full radiosity. You'll need to use pretty high settings on radiosity and/or AA to avoid flicker. Once you achieve a flicker free 1 second sample you'll have a far better grasp on how much render time will be required and be in a better position to decide where you'd like to cut render corners if necessary.

rustythe1
10-27-2015, 11:55 AM
also try using large area lights instead of radiosity, it can often give the a good soft effect but a lot quicker, I often use it myself, some set ups I just use a single large area light in one direction, then a second les bright one with shadows turned off in roughly the opposite direction (also I tint it blue to give a cold effect in the shadows), you can also add the odd point light and just set them to affect only spec and to give shiny areas some highlights, I have done quite a few animations this way and have 1080 frames often coming in under 20 seconds (sometimes faster than VPR!) although I do have an 5980x 16 threads so that helps a little too:)

Scazzino
10-27-2015, 12:20 PM
Absolutely! That's why I suggested an animated render test first to see how long the renders would be to get rid of any radiosity flicker. It's often not worth the render time for animation unless you can cut corners with things like backdrop only radiosity, or rendering in layers and compositing, or pre-baking, etc. Or if you have a massive render farm available with unlimited horsepower of course. Using area and point lights instead will render orders of magnitude faster.

tyrot
10-27-2015, 07:40 PM
buy Octane renderer..

Scazzino
10-27-2015, 10:04 PM
Yes, that's another good solution if you are running an NVIDIA graphics card and don't mind buying the plugin and/or standalone renderer.

madno
10-27-2015, 10:27 PM
Never tried myself but,
could he just first render the room with GI as an exr panorama and then use that later to light the character animation?

Surrealist.
10-28-2015, 06:03 AM
I have done quite a lot of render testing with GI in interior scenes. There is absolutely no doubt that the render times skyrocket out of control on interior scenes for character animation.

In a perfect world I think the lighting sets ups are so much simpler if you can get away with simply lighting it once as if it is in the real world and go. But that requires a boat load of power. Going down from there, you have various degrees of compromise or ways to fake it.

And the most obvious one, is the same trick they use in the real world in studios with a break away set. In most cases you won't be filming a shot that takes in all angles of the room. So you can plan your set up on a shot by shot basis. And by breaking away parts of the room you don't need, you can save render time dramatically by not having the set fully enclosed and relying on bounced light all around.

I like the baked scene and shadow catcher approach. I have done something similar where I shot the background with GI and the character was lit exclusively with other lighting. Quite a lot of savings there.

So in theory a baked set and shadow catcher is a viable alternative to the real thing.

But one thing is for sure. Absolutely for GI in interiors with Characters you are going to need a lot of power or tricks that sacrifice quality. And this included all GI tricks out there presently in video tutorials. And there are some good ones by RH on this subject. But even those tricks take the hit of sacrificing quality and control over your lighting. There is absolutely no way around it.

So beef up the power or take cascading levels of hits on quality on a shot by shot basis.

Scazzino
10-28-2015, 10:52 AM
Agreed!

One thing I've done is baking occlusion maps and then using the old tried and true spinning light setups for the fastest possible rendering. It's a little more work to set up with spinning light rigs but the render times are VERY fast because the AA you need anyway smooths the spinning lights out as if they were area lights, but at the same speed of point lights. This lets you use many more point lights as if they were area lights. I wrote a chapter in my book (http://www.amazon.com/gp/product/0763782645?ie=UTF8&tag=telebitescom-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=0763782645) about the spinning light approach which you can browse through online at Amazon.

So you can try the following to see which works best for your situation...

Full radiosity with a powerful render farm.
Full radiosity with Octane render.
Background only radiosity.
Interpolated radiosity with radiosity cache (YMMV)
Pre-rendered radiosity for set with character animation composited on top.
Area lights (perhaps with background radiosity).
Area and point lights.
Point lights with spinning light rigs.

squarewulf
10-28-2015, 02:11 PM
buy Octane renderer..

and $1000 worth of video cards.

ActionBob
10-28-2015, 03:18 PM
$1000.00 doesn't quite cover it for me... :-/ and I was thinking of putting a third card in there..... :-(

I need a new hobby - or start making some money with this stuff again.

-Adrian

squarewulf
10-28-2015, 04:06 PM
$1000.00 doesn't quite cover it for me... :-/ and I was thinking of putting a third card in there..... :-(

I need a new hobby - or start making some money with this stuff again.

-Adrian

Same, but I need a bigger mobo/case first. I currently only have 2 gtx970's ~$800. But it gets the job done.

m.d.
10-28-2015, 06:08 PM
octane render with 1 video card and use the octane render cloud....should be out of beta pretty soon, instant render farm

power equal to thousands of 680's, with 4 GPU's rendering per frame, and more if you need it

their assumption is a sequence of hundreds of frames will render faster then your local machine can do the first frame. All flicker free of course.

Pricing not yet set though....

gamedesign1
10-29-2015, 12:18 PM
Thanks everyone for all your replies. Lots of things there that I had been thinking about as well. One thing I didn't think of was Octane, purely because I thought it would be too slow. The grain/noise etc. I use to use fryrender a long time ago to do physically based lighting and it really needed a long time to get rid of that grain. I only have a NVIDIA GeForce GTX 750 Ti card and only 1 slot in my motherboard. Plus I don't really want to spend too much at the moment as I am in the process of moving etc. I would love to be able to try Octane out one of my own scenes to really get an idea of the speed of it. Using that online demo doesn't really tell me much.

I have played around with Blender cycles and that seems like a really good renderer, but it does take a long time to clean up the noise on my machine (i7 2600 12GB RAM).

I have been using Rebus recently (render farm) and they seem good and not bad prices considering.

gamedesign1
10-29-2015, 12:34 PM
Never tried myself but,
could he just first render the room with GI as an exr panorama and then use that later to light the character animation?

I was wondering about something like that. it would be great to be able to generate an hdr image from the location of the character then I could use that to light it. Does anyone know how to render an HDR image taken from the scene's lighting?

UPDATE: Actually I remember using the advanced camera in LW to render spherical maps, I'm going to try that :)

Surrealist.
10-29-2015, 09:47 PM
Another thing to absolutely consider is baking the scene itself with AO maps and even lighting to UV maps. I mean rather than baking radiosity cache. Basically create all of the look of the background baked to images. Using a workflow like you use with Quixel and Substance Designer for games. But here you can user larger maps. Then you simply exclusively light the set with a few point lights. And then Exclusively light the character and floor with radiosity. Fake any parts where the character walks in front of a light source with a light focused on that area.

Attached is a scene that was fully baked in this way.

130626

Basically you get 0 hit for environment lights.