View Full Version : Pause Rendering

05-18-2003, 07:14 AM
A simple thing I'd like to see in a future release of LightWave is a very useful, I think : I'd just like to be able to pause a rendering that would let me take the control of my computer when I have an urgent thing to do... (I don't know for you, but it's always when I do a render that take ages to render that I'm asked to do something quick, and, in this case, I must wait for my computer for every single thing I do :( )
In the same time, the ability to stop rendering and be able able to resume it would be appreciated (like in this great render engine : PovRay ;) )
I think it must be easy to implement such a feature, so if you think the same thing as me, please ask for this function...
Thanks :)

Capt Lightwave
05-18-2003, 12:09 PM
Why don't you just render to an image sequence instead of an animation file? With image sequences, you can stop the render at any time and do whatever you need to do, and then resume rendering whenever you're ready....

Image sequences gives you a few other advantages but we can take that later if you'd like....

05-19-2003, 04:57 AM
You don't understand what I've said, which is not a surprise for me, because of my very bad english ;)

I do use image sequence all the time, and never render to an animation file, because when you use an codec directly in LightWave, it produces artefacts that don't happen with quicktime pro, for example...

No, what I meant was when you have to render to a very big file (let's say 4000*3000 with radiosity, in other word 5 or 6 days :( ), You can't actually pause the render like you do in After Effects, or in other 3D render programs like PovRay...

And I think that's a shame, because it would be so easy to implement...

But, if this feature never come, like I think it will happen, I will continue with doing my stuff like now, very very very slowwwly ;)

05-19-2003, 05:33 AM
It may be really easy to implement, still I don't see the sense in it. LW would still hold all buffers in RAM and possibly even consume CPU power to refresh the wait state from time to time (avoiding data loss thru RAM fragmentation) so there may not more power left over than when rendering normally. BTW, you could always try to lower process priority for LW (works fine on Windows and should work on OS X via command console) to give your computer some more air for breathing.


Zafar Iqbal
05-19-2003, 11:20 AM
Just give LW a lower priority using Task Manager and you are set.

05-19-2003, 11:54 AM
Ok maybe pause the rendering process can even increase CPU or resources compsumition but thatīs only if that information is loaded into Ram. Now what happen if all those bytes can be saved atomatically in the hard drive after a quick dialog box or something like that? I see no problem in that.


05-20-2003, 01:29 PM
Thanks Christian for your post, I see that at least one person seem to understand what I mean ;) That's a great victory for me, someone can follow my thoughts in english ! :cool:

By the way, the feature I'm asking for is not just the possibility to lower the thread priority, but also to stop a rendering and be able to resume it later, when my machine does have free time, which is not so often...

The other reason I'm asking for this feature is because I'm not always working on a PC, nor on Mac OS X, but sometime on Mac OS 9, which doesn't seem to give me the ability to lower the thread priority :D (correct me if I'm wrong ;) )

So, that's why I was asking for this feature, and also because I think it would very easy to implement.

PS: I know that some of you will ask The question : "why are you still running LightWave 3D on Mac OS 9 ?"
And I'll answer : "because in some french post-production company, we are still using programs like photoshop, after effects and Final Cut Pro with OS 9, so you have to do with this system..." :rolleyes: and I'll add : " On some rendering task, Mac OS 9 renders faster (by 20% in some specific case) than Mac OS X !!" :cool:

Thanks for reading,
Laurent aka Tartiflette :)

05-20-2003, 01:57 PM
Salut mon ami Tartiflette.

BTW, j' aime Annecy beaucoup, et le festival du film animation =O9

About pause rendering, and storing the calculation on HD,
some calculations are very sensitive and sometimes farms have same brand CPUS, and same generation of CPUS, to prevent jumping of frames due to slight miscalculations.

(actually I dont know if LW code is so inteligent to solve such problems)

But, just in case, calculations like Volumetrics, Raytraced Reflections, Refractions, DOF, Radiosity in particular, are very sensitive.

You render a frame with MonteCarlo with F9 and save it.
You render the same frame again, the two frames have slightly different dithering. A possible "pausing" could show a stripe of pixels at the pausing area.

In the past, some people asked if it was possible for LW to spread the rendering load in the form of "tiles" so a network can render the same frame. Unfortunately LW wasnt written for this purpose from the beginning, and such features (I admit VERY COOL) need some rewriting. Let see LW[8] ...

05-20-2003, 06:02 PM
Well thatīs very true my friend, as you say some calculations can behave in a "tricky" way. In Radiosity this appears as banding when the rendering process is divided as you can see in Markos rendering due to LWīs sthocastic method for Radiosity calculations...i donīt know what happen whit renderfarms and "normal" raytrace rendering coz I've never work with renderfarms.
In any case, I think is possible to save some work with ease.