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View Full Version : URGENT : Frame Rendering times get progressively longer



mis
06-24-2013, 12:22 AM
i see this has been posted before with people haveing simular problem

i have a deadline this thursday on a project
and i have a problem :(

i have a scene setup with global illumination interpolated
and i use gi cache to get rid of flicker

but when i render as animation the rendertime progressively gets longer each frame
though there is slightly any change in the scene but some small camera movement.

i know gi cacke calcs alittle extra on each frame but thats not the problem

its when rendering each frame adds like 30-40 seconds to the render
so when frame 1 takes 10 minutes then i come to frame 10 its like 17 minutes and so on
it does seem to stop at a max someware but right now frames are taking
27 minutes to render insted of 10

and the weard par is if i stop it and start it again
or test single frames with a normal f9 render they all take around 10 minutes


its only when rendering animation it builds up

how can i fix this problem without enlargeing my rendertime inzanely ?

Urgent if you can help please my deadline is close

BTW ime running lightwave 10.1

Waves of light
06-24-2013, 01:11 AM
Mis - it's the GI cache. It get's added to each new frame when there isn't enough existing samples meeting tolerance and angle.

Taken from this thread (Sensi's response): http://forums.newtek.com/showthread.php?120918-Frame-Rendering-times-get-progressively-longer

As for a quick fix (other than the spinning light trick mentioned in the thread above), there maybe someone with better knowledge in that area along soon.

Hope you get it sorted.

3DGFXStudios
06-24-2013, 01:12 AM
Don't use cache at all. You can get pretty and fast GI without it. What are your settings. What are you trying to render. Are there a lot of transparent surfaces that could be excluded for example?

mis
06-24-2013, 02:04 AM
its some minor panning inside a house
ime running montecarlo interpolated
there is glass in the scene but ime not running transparency on, in the gi panel

settings is intensity 3-400 depending on the arear bounces 2-3
aprox rays 150 2nd 80

minimum maximum 2 50
angle default multiplyer default

and cache is currently set to on and Automatic

djwaterman
06-24-2013, 02:38 AM
I think it has something to do with the Cache Preprocessing panel, there are 4 choices Auto, Always, Never and locked.
This guide is well explained but still confuses me in the way it's explained, but it should help.

http://www.except.nl/en/#.en.articles.79-except-lightwave-96-radiosity-guide

I've forgotten exactly what you're meant to choose for a walk through type animation, or even how to bake the radiosity cache, but I think that's what you need to do.

3DGFXStudios
06-24-2013, 03:10 AM
If it's really just a panning motion what you are doing why not render one really wide frame and do the panning in compositing.

If you decide to turn of cache you need to up the rays a bit. In most cases 1500 is good for interiors. The 2nd rays not to high 20 could work fine. But it all depends on your scene.

Waves of light
06-24-2013, 03:28 AM
If it's really just a panning motion what you are doing why not render one really wide frame and do the panning in compositing.

What a clever 'thinking outside of the box' idea.

mis
06-24-2013, 04:15 AM
i know that would be a posibility however that is clearly visible in the image do to the fact
that objects dont shift in distance while panning giving it a look that is not so "live"

am i making sence

Thats why ime animatiog its not just a pure scroll with nothing

3DGFXStudios
06-24-2013, 04:19 AM
If you pan object don't shift. You won't see any difference if you render one wide frame or pan the LW3d camera. Only when you move you have parallax change.
Why do you think a HDRI sphere works.

mis
06-24-2013, 04:45 AM
not that it solves my render time problem with gi cache but ill defenetly take it into consituation 3dgfx :)

Danner
06-24-2013, 05:01 AM
its some minor panning inside a house
ime running montecarlo interpolated
there is glass in the scene but ime not running transparency on, in the gi panel

settings is intensity 3-400 depending on the arear bounces 2-3
aprox rays 150 2nd 80

minimum maximum 2 50
angle default multiplyer default

and cache is currently set to on and Automatic

I think the problem here is that you animated the intensity, you's be better off using a fixed intensity, use a floating point format for export and vary the exposure in post. If you don't animate the intensity then you can turn off animated cache wich is the real killer. Your settings are low for non animated cached radiosity so after fixing the intensity up the settings to something like RPE 800 SBR 400 MPS 3 maxPS 100, that should be in the ball park, increase rpe if it's still noisy. Now set it to auto, clear it if needed, set a frame step of around 15, (20 is fine if the camera is slow) then do a "bake radiosity scene" wich should take between 1-2 hours depending on scene, then lock the cache, save the scene and render. Radiosity process will be 0.0 seconds now.

3DGFXStudios
06-24-2013, 05:04 AM
Not using cache would solve your problem. I stopped using cache because 9 out of 10 times it's slower then just rendering a full radiosity calculation and it's behavior is not predictable which is not really handy if you are trying to make a deadline.
What also can speed up rendering is turning thing of you don't need. For example diffuse or shadows on lights. Lower the shading samples if possible. Turn of volumetric radiosity. Turn off occlusion...... Things like that.

mis
06-24-2013, 06:03 AM
danner my settings is not animated
its just inbetween that value that its set on most of the scenes right now

Danner
06-24-2013, 06:05 AM
I disagree, it's much faster, and it's very predictable.

3DGFXStudios
06-24-2013, 06:23 AM
In simple scenes it is faster and predictable but in most of my work it is not. And rendering isn't a problem for us because of our render farm.

sukardi
06-24-2013, 06:25 AM
If you are rendering an animation using cache, always use 'bake radiosity scene' first and then set cache to 'lock'. It is the only way to get stable and predictable result...

Nowadays, I just throw in non interpolated with ray of 8 and then try to reduce the noise in post...

mis
06-24-2013, 07:54 AM
what are you saying sukardi, Non Interpolated montecarlo and only 8 rays per eval ?

3DGFXStudios
06-24-2013, 08:02 AM
That would result in a flickering render (if not cached) with no detail in the radiosity.

mis
06-24-2013, 08:14 AM
same is my thought thats why i wonder :)

mis
06-24-2013, 08:48 AM
i have now tried baking scene with every 10th frame and then changed cache to lock

and i have now rendered the first 12 frames and they have so far NOT rized in rendertime
every one is around the same time, so it so far it seems we are on track of a solution to the problem
ill rapport back when i know futher

sukardi
06-24-2013, 04:15 PM
what are you saying sukardi, Non Interpolated montecarlo and only 8 rays per eval ?

Yes, but it is not for everyone but something you can consider depending on your scene.

Using non-interpolated, the details are perfect and you don't need to worry about cache. Definitely does not work for interiors. Motion blur is a pain, so I normally add those in post.

It is the most stable solution that I can find but the noise can be really bad without insane render time and you don't get those nice multiple bounce effect. I try to fix/ add to those in post...

bobakabob
06-24-2013, 04:49 PM
i see this has been posted before with people haveing simular problem

i have a deadline this thursday on a project
and i have a problem :(

i have a scene setup with global illumination interpolated
and i use gi cache to get rid of flicker

but when i render as animation the rendertime progressively gets longer each frame
though there is slightly any change in the scene but some small camera movement.

i know gi cacke calcs alittle extra on each frame but thats not the problem

its when rendering each frame adds like 30-40 seconds to the render
so when frame 1 takes 10 minutes then i come to frame 10 its like 17 minutes and so on
it does seem to stop at a max someware but right now frames are taking
27 minutes to render insted of 10

and the weard par is if i stop it and start it again
or test single frames with a normal f9 render they all take around 10 minutes


its only when rendering animation it builds up

how can i fix this problem without enlargeing my rendertime inzanely ?

Urgent if you can help please my deadline is close

BTW ime running lightwave 10.1

Just a thought.. Have you checked to ensure the image viewer isn't accidentally switched on and minimised? If so it can stack up rendered frames, eat up ram and slow things to a crawl.
Otherwise best switch of cache and use interpolation. Flicker won't be that visible with decent aa.

mis
06-25-2013, 12:01 AM
i have now checked my next scene and ht has been rendering 10 hours now and it has not rized in rendertime like before

so if anyone get into the same situation like i did
it seems Baking the scene every x frames ( i did every 10th) and then locking the cache before rendering
has done the trick here it seems :)

Hope this can help others with this problem

JonW
06-25-2013, 01:07 AM
Good that you got it working!


Next time:
I asume there is nothing moving in the scene & no lights changing brightness, then "Bake Radiosity". If I have say 900 frames I do every 100th frame first at a higher camera resolution. Then normal camera resolution, every 30 frames, then every 4th to every frame to fill in the gaps depending how long the Baking has been taking. If you bake every 100 frame first you get a good idea of how long baking every frame is going to take across the scene. Then you could do all the odd frames first, & if it doesn't take too long, do the even frames starting with frame 2. Then Lock the Radiosity & render.
You can also Bake with as many different cameras as you like!

You will only get an increase in render times only if later in the scene there are more reflections & or transparency (eg difficult things), then render times will go down if the end is simpler to render. Without Baked Radiosity render times keep going up.

Check WTM for computer efficiency to see how efficient LW is using the CPU. If it's around 80% & you have enough RAM start a second instance of LW & render frames "starting at 900, finish at 450, Step -1" for example.

mis
06-25-2013, 02:05 AM
hmmm i think i read someware long ago that if i rize the render resolution say, for print or so
it also doubles up the gi points and aa needed or somthing like that
so if i render real big images of the same scene i should lower the gi resolution or aa resolution
or somthing like that

somthing about that it meshures per pixel and not cm or somthing
so if the image gets really big its alot more pixels to sample if its like min max 2 50 or so

Not shure if its true

any of you guys aware of such formula ?

JonW
06-25-2013, 03:09 AM
hmmm i think i read someware long ago that if i rize the render resolution say, for print or so
it also doubles up the gi points and aa needed or somthing like that
so if i render real big images of the same scene i should lower the gi resolution or aa resolution
or somthing like that

somthing about that it meshures per pixel and not cm or somthing
so if the image gets really big its alot more pixels to sample if its like min max 2 50 or so

Not shure if its true

any of you guys aware of such formula ?


If you double the size (ie 4 x the area) every thing take four times longer. So you have to make AA 1qtr, to roughly match the original render time. You basically double the size to fix AA edge issues & flickering. You can also lower the AA say by a half instead of to a quater, render times will obviously go up but in effect you get extra AA when you resize the image.

Unfortunately any animation needs much better setting than a single render. Things like edges, flicker, general quality of AA are simply brought to ones attention in an animation which would not be an issue in a single frame.

Also you really need to keep Multiplier at 100% for single frame, one can get away with 50 % or even 25% if you are in a hurry & your customer is not a pixel peeper!

Unfortunately one has to have high quality setting for an animation.


With LW 11 quality of render & AA has changed quite a bit so edge AA is not quite the issue it was.


If you can get just 1 other computer rendering as well you can half your render times. But takes time to set up.

mis
06-25-2013, 03:22 AM
well i was thinking of situations with big still images
i would not render anim double size and then scale it down :)

sadly i dont have the gold to upgrade my 10.1 to 11 yet
but i hope to find a sponzor some day :)
so i can get into some of the new stuff

JonW
06-25-2013, 04:48 AM
Can you "steal" another computer?

A second computer even if it's old will help. Getting Screamernet up & running is worth the effort (while the pressure is not on) The day those first frames come flying in from here, there & everywhere is very rewarding.

The hard thing with SN is initially working out what is going on. But once there with the first 2 computers it is then so much easier setting up more computers.

mis
06-25-2013, 04:59 AM
ime not the type that steals :)

however yes i have been working with lwsn some years back
but to be frank its alittle hmm not so optimized that you need
to share drives and do this and that and make dos scripts and crap

i am going to test an alternative that seems to be alot easyer
and more smooth wich also supports single frame

Amleto is the name
a network thingy that has become free for lightwave
wich have nice insaller and client you just start
with server interface and all
and it detects clients by itself automaticly and other nice stuff
and it runs its own transfer protocol somehow so you "what i have heart" dont need to share a ton of folders and crap.

so very exciting to test that.

i installed it last night on my main computer and installed the and ran server and client , startet up fine
so i installed client on one of my other computers to test and it started up, scanned, found server and trying to connect to it
and then CRASH, The application has stopped working....

so i wrote them a mail last night if they are familier with that problem and how i could fix

JonW
06-25-2013, 05:14 AM
I tried Amleto & also have a BNR licence but had problems with my main computer, Other computers work fine but not the one I wanted!. Back to SN, it is worth reading Matt's tutorial & getting SN running this way even if you do not use it in the long run. It just gives you as insight at a base level of things & you are considerably more well armed.

Once you get the Bat Files working you can almost edit them blind folded after awhile!

mis
06-25-2013, 06:49 AM
i know :) i have been using lwsn for years
just getting sick and tired of the way it works

and so much coolness has happened in lightwave and modeler
but lwsn is still just an old dos file, that seriously should have been rebuild like some kind of windows service
so you dont need to run around and turn on and off cliends on each computer and stuff + share drives here and there and setting up firewall and what not

it need a 20xx update of dimentions

Danner
06-25-2013, 06:58 AM
I got amleto 3.2.0.2 beta to work. It did hang the first time I tried so I changed two things not sure which one stopped the crashing. I added a network drive in the options (you have to name it or it won't stick) and I packaged my scene, then pointed amleto's content to that package. BTW Cache did not get copied while doing the package scene so I had to copy that by hand.