Skip Rendered Frames Button

[peliosis]

Well the title nails down the question:)

How to achieve the magic effect of skipping rendered frames while rendering a sequence?

Pre frame script? or another hell.

[peliosis]

Ha, I got you! nobody knows...any bonus for extra hard problems?

[michael]

do you mean something like a sequence of frames say 1-100 but a few of those frames are already rendered? and you don't want to re-render them?

or render every 10th frame or 2nd frame etc?

for the later there is an increment parameter on the frame range thingy...

as for the former I think you'll have to test to see if the frame is already there with a pre-frame script...

[sibarrick]

You would have to write your own render script to loop through frame at a time. Then before each frame do an uls on the file to check if it exists.

[peliosis]

You would have to write your own render script to loop through frame at a time. Then before each frame do an uls on the file to check if it exists.

28089[/snapback]

yuck, I knew it, thanks.

Arctor I meant if you render a sequence and your machine goes dead in the middle, then you just restart houdini, reload the scene and hit "render" to compute only missing frames, not overriding existing ones. Now you have to manually readjust the range.

Now if you have a few more machines that is also handful because you don't care which of them render what, but throw the same scene on each and you are sure frames won't overlap.

Mental creates a placeholder each time it begins a frame so the other computers know which frames are being processed and proceed with the next.

[sibarrick]

If you render ifds first it's easier to manage. Unless it falls over rendering them of course.

[peliosis]

If you render ifds first it's easier to manage. Unless it falls over rendering them of course. 

28097[/snapback]

Yeees, but it's beginning a little time and resource consuming.

I was accustomed to rendering the scene as a whole and apart from huge scenes everything was allright. Now I have to render everything separately and these ifd's yet. I wonder what are their practical advantages if I'm not going to dig into them and change something in text editor ?

I'd rather have a scene with everything set up and run it to render different rops. At the moment ifds look as another redundant rendering step.

If I change anything in my scene I have to rerender all ifds for all the passes. I'm just a little worried about a very simple rendering slowed down by some hardcore production setup. In every other application there just is a button "skip rendered frames".

[sibarrick]

I agree a skip rendered frames option would be good, and perhaps it should be rfe'd.

As for ifds, it shouldn't really slow you down because basically an ifd is generated internally before mantra renders a frame anyway so the time difference is small. The advantage is that you can often generate them very quickly and then off load the render to another machine or multiple machines very easily. Also if one frame falls over you don't lose the whole sequence just that frame. Rendering ifds with mantra only uses a render token and not a full license so you can make use of all the free render licenses that come with a full Houdini.

I guess if you are working on your own this might not seem worthwhile.

Anyhoo here's an example that will render a rop but looking for existing frames. I've made it as an asset that you just give it the path to your actual rop and a frame range, and then check whether you want to overwrite or not. It's an nc file but would be very easy to copy out to a commercial license.

example.zip

Edited May 29, 2006 by sibarrick

[peliosis]

Thanks Simon, I'll have to dig into this hscript thing but I'm not too eager

[malexander]

I was a little worried that adding a 'Skip Rendered Frames' option to a ROP could cause a lot of problems. For example, you start your nightly render, leave, and then come back in the morning expecting new frames and find out it skipped them all Worse, you might not realize that it didn't render and think they were your new results. So I was reluctant to add such a feature (though I agree it is useful in cases).

I think it'd almost be a better as an option on the render command (-R), and a toggle in the Render Controls dialog ("Render over existing frames") - something more temporary, that you have to specify each render.

Or perhaps I'm totally underestimating users... (but I can see myself making that mistake)

[sibarrick]

Well, you could always concider the opposite case that can happen at the moment.

You set up a sequence to do 1 - 1000 frames and it bails out at 800 so you reset it to do 800- 1000 then you make some changes to the scene but forget to reset the sequence length back to 1 - 1000 so you only re-render the last 200 frames. Basically once renders start bailing out it gets to be a pain to manage whatever you do.

One other thing to concider is this, we have guys here who work on an entire animation on their own - much as a freelancer might - and they may have 20 sequences to manage all with different start and end frames, if they don't have time to set it all up with render scripts it can be a nightmare constantly changing the start and end ranges to redo little pieces of the renders. Its much easier to browse through the frames and just delete the ones you want overwritten then just let a script fill in the blanks without having to worry about changing the sequence lengths to match the holes in the sequence. If you see what i mean.

I think whatever the solution be able to manage it in one place makes life less error prone.

[peliosis]

Dear malexabder, in such way of thinking everything can cause troubles.

You have to setup everything ok, that's all, otherwise you can be back in the morning just to notice that you have half of your machines off, because you forgot to power them up or everything is toasted because you forgot to switch off your iron.

It's a standard feature for every renderer out there.

Simon, thats just the way we work, delete and render non existent

[malexander]

and they may have 20 sequences to manage all with different start and end frames, if they don't have time to set it all up with render scripts it can be a nightmare constantly changing the start and end ranges to redo little pieces of the renders

That's why the render command has a -f option to take a frame range, and the Render Control dialog has frame range parameters. The idea is that you don't touch your ROPs at all - if you want to render a subrange, you modify it here.

So, if there were a skip frames option, it should be on the render command or in the dialog, not in the ROP itself. You don't want to be modifying ROPs at all, once you have them set up to your liking. I see ROPs as the Makefile's of rendering. To make different targets, you pass it options, you don't modify the Makefile itself.

The benefit of adding it as a flag to the render command is that you could alias a command to "render -S", like renderskip. Then you could use render or renderskip, depending on what you need, and never have to worry about modifying ROPs or deleting files.

or everything is toasted because you forgot to switch off your iron.

Most irons have an auto-shutoff these days, don't they? A case of the designer being cautious saving some users from an unanticipated result.

[sibarrick]

That's why the render command has a -f option to take a frame range, and the Render Control dialog has frame range parameters. The idea is that you don't touch your ROPs at all - if you want to render a subrange, you modify it here.

28307[/snapback]

Yup that's true, i'd forgotten about that, but it may still mean setting up a bunch of subranges in a script or waiting for each one to finish and then manually setting off the next one. Doing a skip missing would mean that you could just delete the frames you wish to replace and set the render off in one hit.

And yes I agree the best way would probably be to add a switch to pass it as an argument to the render command. It would also show up in the render control... dialog, right? is that what you mean.

cheers!

[malexander]

It would also show up in the render control... dialog, right? is that what you mean.

Yes.

[peliosis]

It'd be great to have it as a command line switch.

Most irons have an auto-shutoff these days, don't they?

28307[/snapback]

My one has only a tv

[malexander]

My one has only a tv

If that's not a recipe for burning holes in your shirts, I don't know what is...