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cresshead
08-20-2009, 07:53 AM
really?...people actually use global illumination and radiosity in animations longer than 30second adverts?

if you put hd res sized frames and a busy scene together do studios really turn on radiosity and GI?

the render hit with bounced light on long form projects such as animated for tv shows or feature films means 100% CG productions have a HUGE render hit to take..

do they actually DO IT???

having seen several breakdowns it seems people use an ambient occlusion pass and shadow, reflection, diffuse passes ect to construct a final comp.

unless your pixar who have 10% of the worlds computers to throw at rendering..who actually uses it?


are we just dumb?...should we just forget global illumination and learn how to light stuff properly?

okay a STILL might go for Gi or RAD but other than that it's probably just asking for trouble with massive render times...haveing just watched jeff lew's breakdown of this render pipe he used ambient occlusion passes and FAKED HDRI for the 125,000 frames length the film was cut to.

??
should we learn how to render with gi or just forget it as a stupid idea that has a limited real world use down to still images and VERY short/small res animations.

let's kick this topic around and get to the bottom line.

4dartist
08-20-2009, 08:26 AM
It just depends. I use it every now and again. It adds a realness that's I find hard to get with spot/distant lights. Maybe because I'm a bad lighter. I now use dome lights instead of GI at times, like shots in orbit. I also have done quite a bit of spinning lights too. Some shots just take too long for GI so I light it best I can. I never have render times over 8mins a frame considering all the elements.

akademus
08-20-2009, 08:30 AM
We use it all the times. That explains some 60 Xeon cores sitting around me :D

And LW GI is damn fast, you should see Vray render times !

4dartist
08-20-2009, 08:35 AM
I want 60 cores... I only have 8.

cresshead
08-20-2009, 08:38 AM
On this little production (www.cargoderfilm.ch) we used GI for 2048x1000 renders, up to 600frames shots.


600frames is what 20 seconds or so...


i'm talking about 100% cg productions like feature films and tv shows that maybe 10mins to 40mins per show in a 13 to 26 show season or if it's a cg feature it would be 70mins plus

when you'r hitting 125,000 final frames and long gi rendertime per frame could make a production impossible or extreemly expesive.

say a HD frame 2K takes 2 hours to render on a quadcore if your lucky, that's a quarter of a million render hours...thats...um....ALOT!:D
like errr....10,416 days....or 28 years...on 1 pc...so if you have 28 pc's that's 365 days to render it out 24hours day
we've moved into HD as the baseline res now for tv, film, internet

cresshead
08-20-2009, 08:45 AM
We use it all the times. That explains some 60 Xeon cores sitting around me :D

And LW GI is damn fast, you should see Vray render times !

yeah one of my friend's renders interior images for arch design and can render for 15 to 30 hours on a single image...

4dartist
08-20-2009, 08:49 AM
Cresshead, seems like you already have convinced yourself that GI takes too long to use on large productions. I suppose you've gotten frustrated lately and are basically just venting? Or hoping your missing some secret setting that all the big productions use to keep render times down?

To me it seems like productions big enough to do episode after episode of all CG animation have farms to use. Small places like where I work don't have a farm, but we also don't put out near as much animation, so either way GI is still a viable lighting solution at times. I could be wrong.

I bet there are CG shows that don't use any GI.

cresshead
08-20-2009, 08:55 AM
Cresshead, seems like you already have convinced yourself that GI takes too long to use on large productions. I suppose you've gotten frustrated lately and are basically just venting? Or hoping your missing some secret setting that all the big productions use to keep render times down?

no just watched the making of killer bean...you either need to own 50+ quadcore pc's or rent the use of them to hit a render tartget as large as HD res running upto 125,000 frames long..it's just a numbers game...IF you go Gi or radiosity...he chose not to and went AO instead.

i'm just sitting here thinking out loud..... is learning the in's and out;s of gi worth it if you have to throw it all out the window when you want to look at making a long form animated project...

i'm going to do some tests in lw as i laready know that mental ray is like running thru a vat of liquid super glue when you go GI on anything complicated.

how FAST is lw compared to mental ray, vray etc?

cresshead
08-20-2009, 09:14 AM
It is a feature film and this were the longest shots - not the only one. I know there is only a handful of shots in the trailer, anyway... Was talking about GI stability and stuff. It's absolutely production ready. We had not a full CG feature, but still maybe 150 shots to do in less than 3 months (Our department - there was the XSI people and the C4D guys. In total I'd say 600 shots. Long ones.). Rendertimes were between 4 and 40 minutes per frame (GI pass). You asked about "production" not "full CG", so sorry if I misunderstood. I thought the project was worth of a "real production". Guess we only played around. With our millions of polys (detail, detail... argh! computers choked...) and gigs of textures... :D

cool yeah i understand you now:thumbsup:

was the gi pass like an AO pass in how you comped it?
also does xsi spit out the gi pass as a part of the main render or idd you have to load that up and render that as well as a color ***..so longer time rendering..

Matt
08-20-2009, 10:06 AM
And LW GI is damn fast

Totally agree, sometimes it's easy to forget just what we have, it's easy to set up, and is _still_ one of the fastest out there.

Without a doubt, a production quality renderer.

wacom
08-20-2009, 01:22 PM
I think it's an equation that goes on a case by case basis really and will continue to be so. How many people on the project, how experienced are they with the render engine, who is doing the comp work, what is the budget, what is the time line for the project and what is the look that is needed?

Plus...as computers get faster...so does everything else...so yeah...GI is faster...but then most of the time direct lighting is faster too (pending you have the time to set it up). There is no reason you can't use both- and it seems more and more people are doing that. Use GI where it makes sense, and go direct where it makes sense. GI for the general lighting, direct for the "painting and directing" with light. You can go really far with 1 bounce simply GI and direct lighting comped together.

Adding things like diffuse convolved environment map techniques
(http://www.xsi-blog.com/archives/248) that render so fast and get you so close in some instances that you'd be hard pressed to go full "GI" if you don't have to.

For me...I've avoided using "GI" solutions for work because...I'm a little fry with only my system and the occasional use of a render farm via rental hours. Some things are just easier to control and do with direct lighting IMHO esp. if "so real I don't think it's CG" is not the goal. And yes, AFAIK LW AO is slow- really slow. I mean...AO is so predictable and stable. Plus the pass is useful for other comp work. Flickering and such are not such an issue and it scales well. (It also needs to be point out time and again that in 99% of images, AO is used "incorrectly" and not comped right for the image. You don't just * it! I've learned this the hard way...)

Maybe it's just me though, but I find GI alone is great if I want to show a product etc. matched to a plate or in very world like lighting, but as soon as the client starts talking mood and gets artsy pasts a certain point it gets more and more difficult to deal with all those bounces and such IMHO. Maybe I just suck though when it comes to such things?

Even if you get all your bounce'n lights from a GI pass of some kind that...bounces things around...there is still a lot that is shader based too... The other day I was looking at an arch viz series of work a friend was having done for him as he plans to restore a commercial space. All the "bouncing" was fine in terms of light (thanks most likely to Vray). However, for the most part, the texturing was lifeless and flat. Metal...hmmm...kind of like metal...wood...well had a texture map of wood...but... the brick texture looked like lambert with not bump/normal/displacement... BORING.

There was a lot more that was wrong too...but I digress!

I guess what I'm saying is there is a lot that goes into a "good render" let a lone "great image IMHO"...so the whole bouncing light thing is just going to help a part of it...right? So the when and if to use it is just part of the over all project equation IMHO.

Mike_RB
08-20-2009, 06:44 PM
All our shots on Iron Man and District 9 use some form of GI and blurry reflections on everything (d9 was mental ray, but the same idea applies). Most of our car ads are the same as well. You pay a time penalty for good looking renders, so you try to work smart to avoid re-rendering 2k finals as much as possible.

erikals
08-20-2009, 07:38 PM
now, was that interpolated?
interpolated has a tendency to flicker.

for interiors though LW GI is no lightning.... afaik

Mr Rid
08-21-2009, 12:22 AM
I have been using LW radiosity for the past seven years in feature production where I am usually integrating CG elements into live plates. Although it does not always give much better result than what I can get with just good lighting/texturing that renders much faster. Dark scenes tend to not benefit much from GI.

jaxtone
08-21-2009, 07:38 AM
Do you think it´s possible to generalize and say just about how much faster render process you´ll get by using "good lighting/texturing" methods instead of radiosity?


I have been using LW radiosity for the past seven years in feature production where I am usually integrating CG elements into live plates. Although it does not always give much better result than what I can get with just good lighting/texturing that renders much faster. Dark scenes tend to not benefit much from GI.

tischbein3
08-21-2009, 07:51 AM
The only real letdown with LWs GI at the moment, and this is where I have to admit you are right in questioning our production in comparison to a CA movie - deformations still don't work. We had some CG astronauts, luckily just a few shots, cause those had to be rendered non-interpolated.

Quick note:
Actually for these kind of stuff the lightb*i*t*c*h* can act as a pretty good surrogate:
Render a small spherical enviroment, and use it to create a lightrig for the characters.

And the trailer looks really nice btw.

chris

MrWyatt
08-21-2009, 08:25 AM
We used finalgathering GI in mentalray on this 84 minute feature animation.
trailer (http://www.youtube.com/watch?v=wbbfr_ukqU4)
:D

Edit: have to admit though that the compression in the trailer doesn't do it justice.

We are also producing a new feature length animation film right now that uses mentalray as well as renderman and we use GI on every shot.

Mr Rid
08-21-2009, 08:43 AM
Do you think it´s possible to generalize and say just about how much faster render process you´ll get by using "good lighting/texturing" methods instead of radiosity?

Depends on the situation.

wacom
08-21-2009, 02:34 PM
The thing is it seems a ratio- how many frames, how large are they, how complex the scene, the time/hours/pay it will take to use direct lighting techniques etc.

I really wish some lighting and rendering TDs would put together a nice set of books or videos on general techniques. The closest I've found that is relevant is that Jeremy Birn book on mostly direct lighting, but it would be nice to see mixed options and techniques on an intermediate to advanced level. It seems there are a million "how to light and render a product/interior" videos/tutorials that are semi-comprehensive, but very little on what to do for animated scenes and/or highly complex ones. Maybe I'm just not seeing them though and they are out there?

Just seems a painfully neglected subject to me...

AdamAvenali
08-21-2009, 02:51 PM
I really wish some lighting and rendering TDs would put together a nice set of books or videos on general techniques. The closest I've found that is relevant is that Jeremy Birn book on mostly direct lighting, but it would be nice to see mixed options and techniques on an intermediate to advanced level. It seems there are a million "how to light and render a product/interior" videos/tutorials that are semi-comprehensive, but very little on what to do for animated scenes and/or highly complex ones. Maybe I'm just not seeing them though and they are out there?

i totally agree. i have watched just about every video for mental ray and lighting/rendering interiors and animated scenes are rarely talked about. jeremy birn also has a dvd now, though maya specific http://www.3drender.com/DVD1/index.htm

erikals
08-21-2009, 03:10 PM
absolutely, i'm doing some tests now, but it is tricky as i'm no professional in that area.

there are a lot of hints on these forums, but it takes a long time to gather them and understand what works, what doesn't, and why.

for example, animating a person together with an interior is completely different from rendering a person in a scenery
(when rendering the interior your rendertimes will sky-rocket)

gordonrobb
08-21-2009, 03:19 PM
I'm involved in making a feature (fan film), which has a lot of full cg shots in it. When we started it a couple of years ago, we were not going to go near GI, but with 9.6, final gather is at best only slightly slower. In some shots, it is actaully faster than the non GI solution. So it's not clear cut by any means.

wacom
08-21-2009, 09:56 PM
i totally agree. i have watched just about every video for mental ray and lighting/rendering interiors and animated scenes are rarely talked about. jeremy birn also has a dvd now, though maya specific http://www.3drender.com/DVD1/index.htm

Very similar to his book (though Maya specific) but it also has a bit more depth. If the clips are like the full deal then it really is edited down. Seems like it would be good to pick up, as even if you don't use Maya, almost all of the procedures if not all could be done in most packages. For LW you'd probably want to use dponts light plugs though.

Still- I wish there was one that covered the other side and in-between. What about more intensive ray tracing and GI techniques and squeezing out good render times? Would be nice if someone like "Saturn" did their own version. Mr. Rid or MrWyatt, maybe you guys might want to? Something with lighting and rendering for animation?!

Thanks for the link though- I'll check that out for sure. I probably should have bought that instead of the nearly worthless mr rendering videos I bought just a bit ago...a little too noob, brute force, and viz for me, and more expensive! Plus the guy was obsessed with using area lights too...

OFF
12-17-2010, 10:54 PM
my test lw animation+GI+motion blur+DOF vs Fryrender
http://www.youtube.com/watch?v=_8ds1WOnS6s

UltraViolet
12-17-2010, 11:10 PM
are we just dumb?...should we just forget global illumination and learn how to light stuff properly?

I was always under impression that using GI is a proper way to do lightning :)

Matt
12-17-2010, 11:29 PM
Just a quick point, lighting interiors WITHOUT Linear Workflow makes everything much more difficult!

LWF is not just for interiors of course, but it's where you see the most noticeable results.

archijam
12-18-2010, 12:30 AM
cress - ive been experimenting with a mix .. some gi, some baked .. can work very well ..

erikals
12-18-2010, 01:17 AM
bake when you can :]

OFF
12-18-2010, 03:09 AM
archijam
can you explain you method?

archijam
12-18-2010, 04:05 AM
OFF - Maybe I can post an example and test scene later.

ie. there is always some tweaking, as, like getting shadows on a front projected gorundplane, you have to mix any (unbaked) shadows with the luminosity levels of the baked surface.

Plus you need UVs.

Will post something simple soon :)

OFF
12-18-2010, 05:30 AM
thanks!
i thinking the same way

3DGFXStudios
12-18-2010, 06:15 AM
We always use radiosity in our renders. It can be fast if you cache it for example or if you exclude transparent surfaces. Also sometimes a radiosity object overwrite speeds things up. Of course it's good to have lot's of cores. ;) . I think a lot of people don't know how radiosity works and crank up values to high and enable functions they don't need, which obviously results in slow renders.

dandeentremont
12-22-2010, 02:44 PM
I'm a big fan of radiosity, but it sure can be a beast (or a big splotchy mess) in some situations. I find it necessary most of the time if you need to make anything photoreal.

Speaking of Pixar and their small island made of render nodes:
In Toy Story 3 (and i assume the others), Pixar avoided using radiosity to give it the look of the old films. (http://features.cgsociety.org/story.php?story_id=5819)

archijam
12-22-2010, 03:28 PM
Here's that bake example.

One object is affected by GI, the other is the baked result, remapped onto a simple Atlas UV. In this case, the whole process including modelling would take about 10 minutes if you know what you want.

Check the differences in setup of the properties of each object.

The surface properties of the baked box need to be balanced with the lighting - diffuse and luminance (see shadow). Perhaps there is a more straight forward way of dealing with this :)

I can imagine this being useful in many situations:
- on all the instances in a large world scene (basic 'AO' effect from the world GI)
- Any large complex background object without movement
- Especially in scenes without light movement, tho this is not nec. required

GraphXs
12-23-2010, 10:32 AM
It would be nice to have presets for LW GI for animations, interior, exterior, FG, MC, Background, interpolation, etc. Some of you who have had success with LW GI for animation; do ya mind providing sample scene and what the GI setting is good for?

I've only used LW GI for baking maps only; I would love to use it for animations but my test are usually noisy. I've only done test with interpolated FG.

V-Ray and Max have spoiled me. It gives nice easy drop downs for it’s GI settings. (Not that everything is perfect) It’s just quick for the most part and overall pretty clean for animation. I want that easy in LW.

archijam
12-23-2010, 01:17 PM
Graph -

Agreed heartily.

This is also the BEST way to teach yourself.

Between the 3 (or so) presets, what values are changing, and by what amount? which stay the same? This is crucial for new users of LW .. and some old ones too ;)

Danner
12-23-2010, 02:33 PM
I acutally find Lightwave's radiosity to be quite fast unless you use animated cache, thankfully I mostly do arch-viz so I hardly ever have to use that.

When a scene is rendering too slow the usual suspects for me are: Too much geometry, too many reflections, too many transparencies, too much refraction, abuse of blurred reflections/refractions, or incorrect antialias settings. My HD-rez renders are usually under 4 min on the dual xeons. For interiors my lights are almost always cached shadow mapped spot lights with 3-6k rez. For exteriors I use a distant light and a textured environment using a gradient backdrop with 150-200% layer opacity.

After the scene is set up I turn off reflections and bake the radiosity of the scene with a 10 - 20 frame step (depending how fast the camera moves). Turn reflections back on and render.

My radiosity settings vary, but I start with:

Interpolated
blur background
Intensity 100%
2 bounces
500 rays
16 secondary bounces
Min pixel spacing at 10
Max at 100
Multyplier 100%
I turn off "use behind test" unless I have some geometry that is right infront of something else (like a painting on a wall).

I usually use Final Gather, but if it's taking to long I switch to Monte Carlo and.. yes, sometiimes it's faster!

I often set the scene so it's a bit dark, then use gamma to correct it, that way I get some extra shading like you would using a linear color space workflow but with little hassle.