Render strips

[CCS]

Hmmm. Interesting.

So who's gonna volunteer to run a few tests?

[olitech]

ok...i guess i'm on crack about the speed part...

I just did a calc to 3000 pixels (1.2million faces):
single calc: 7m48s
incremental: 7m18s

single calc...out of 4 machines i tried this on, 1 crashed

This was a real ghetto 'test'....just had to see

[dlparisi]

A few questions....

1. Stability and usability aside, how does rendering out in strips compare in speed to using DR? Are there any other advantages?

2. Is stripe rendering only available in Max (i.e. not VIZ)?

Thanks,
David

[panthon]

From my own experience I can tell render strips overcomes DR when it comes to stability. Dont even try DR in complex scenes if your host machine has not the 3Gb thingy, because if it crashes, everything does, although the other machines contributing to DR could go on rendering, but the main machine is not responding, so they stop. So, if it crashes, speed is zero

Render to strips (many!) is also more memory friendly, so u can find yourself sending 50+ strips to backburner in order to avoid memory crashes. I´ve found this is sometimes the only way to get the job done, combined with dynamic memory switch, of course

[CCS]

In addition to what panthon said, strips use BB which also allows you to stack a series of jobs. DR works (when it works) only for the current camera/frame.

That said, I would still love to use DR more for working renders/image previews. I have just found it far too unstable to use.

[tricky]

ok...i guess i'm on crack about the speed part...

I just did a calc to 3000 pixels (1.2million faces):
single calc: 7m48s
incremental: 7m18s

Is this just conincidental that doing it incrementally is a wee bit quicker? I would have thought that the 'setup' time associated with this incremental method nullifies any speedups gained.

Anyone else using this method?

[gilicom]

i find it much better quality to render a final render at -5 , -3 irr map then to render it from a pre calc map at 1/2 the size at -3,-1.
I think it will also take around the same time but thats just me
i use pre-calc irr map only on animations.
btw
when u use pre calc irr map on stills do you turn off light cach or use a pre calc one as well?
Gili

[arobbert]

Going back to what olitech said. You could do alow res calculation early on in the process and gradually add more as you refine the project. I need a smaller GI calc for doing previews early on. Using imcremental add you would always be able to subtract the time invested in the earlier calculation. I rely on DR for fast previews.

[Infrared digital]

What if I have to cancel the animation before its finished?

Is there a way to stop it and then have it compile the strips into frames ?

Thanks

N

[Clifton Santiago]

I can't believe this thread is still alive... I've learned a lot about strip rendering with Vray since I started it.

@ Infrared digital: Do you mean you are using render stripes with animation? I think the main purpose of strips is it allows one to render still images with multiple machines, sort of like DR, but slower and more stable. When I do animations on backburner I just have one frame per machine, in which case there would not be a splice pass. Though I guess if you were doing high-res frames, strips might be useful.

Sometimes I will stop a still strip rendering before its finished because the last couple strips are taking too long. In that case I copy the last strip and rename them. Once you do this, the splice pass will kick in and make them into one image. I guess you could do the same with frames...

[Infrared digital]

Hi Clifton

Thanks for your reply.

I am using BB to render to strips because this is the only way I can utilise both machines for this animation. So, I am 30 frames in but there are 15 strips to each frame so, don't want to start farting about with so many strips and mess it all up !

Just to clarify, when you cancel - how does the slice pass know to kick in? I did it yesterday and nothing happened.

Also, the BB Monitor has a second Job called second pass - is it essential to activate this somehow ?

Regards

N

[Clifton Santiago]

I guess I misspoke. I do not cancel the strip rendering, but instead "finish" it manually. If say there are 2 strips remaining, I would just copy the last strip twice, and rename them sequentially to match the rest. What happens then is the second pass, which is what splices the strips together, thinks the stripes are finished and it kicks in. Then of course, I would go into photoshop and crop the repetitive stripes out.

The problem is I don't know how this works for animations. I don't know if it splices the frames together after each frame's stripes are finished, or it does them all at the end.

But what I don't understand is why you need stripes to make your two machines render the animation. With animations, backburner will send different frames to each machine, so it divides the rendering work to each machine without needing to use render stripes.

[Infrared digital]

The reason I am using strips is because the model I am animating has caused me unbelievable problems with unhandled exceptions.

The main machine has only just been able to render the animation when I refined the model and overcame a specific problem that I am sure is a Max bug.

Anway, render times are really high so, in order to get the second machine working, the solution was to render it out as numerous strips and get the 3Gb switch happening also so it didn't run out of memory.

If the merging of the frames happens at the end, how can I possibly know how many frames will be done in a night ? I don't want to cancel it and have upwards of 500 strips to put together.

There is a solution to everything - its just a matter of finding it.

n

[Clifton Santiago]

Okay, I understand. Well I would use a fast test scene to check when the splicing pass occurs. Also, maybe render the animation in pieces to make sure it finishes overnight.

You definitely don't want to manually splice things because not only is it time consuming, but Max doesn't necessarily render at the pixel height specified (even with overlap set to 0). You may try and have a 10 pixel strips, but it might render them at 32 pixels anyway! Which means it is taking 3 times longer to render, and also making it even more difficult to manually splice. But if you do larger heights, like 30 or more, there is less (or maybe none in some cases) overlap.

I have tried to get the buttholes at Autodesk to tell me why this happens by posting on their worthless forum, but no one answers. I guess I would have to call their £60 a minute(or whatever it is), helpline to get an answer. No one on this forum or others seems to know either.

Anway, good luck.

[Candelero]

@ olitech

*Let's say your final is 6000 pixels across...so single frame at 375-incremental add-750-incremental add-1500-incremental add-3000.
...and make sure you check 'don't render final image' after the first calc.

Can you just tell me 1 more thing about that.

Do you touch the min/max passes in the IR map, or you just increase the res.size ?

do you do it like:
1st calc -5/-2
2nd calc -4/-1
3rd calc -3/0

or they all are the same ?


Best regards,
nikki Candelero