Large Render Size - Question

[andyc]

Has anyone tried to render an image 30,000 pixels wide? I have a request to do so with a particularly complex scene, think stadium complexity and you are not too far off.

Any suggestions?

(Yes, I have explained viewable distance and print res etc etc)

Thanks!

[sea2stars]

Using regions, render it out in in manageable strips and reassemble in your favorite image editing software?

[andyc]

That could work, im just worried about the IR build which im presuming is going to have to be one machine. even at 1/2 size its a 15000 wide IR. eeek!

[glorybound]

Strips

I have been using the Backburner strip render on several machines and it is wonderful.

[dcullipher]

I have done this for a billboard. Strip rendering as stated by glorybound.

The light cache wold be the longer part so do that on you beefy machine. The IR map you can distribute across the farm.

[august]

47240

I just did one exterior at 47240x9000px. I used region render and 6 vrimg, 64-VRay, 8GB RAM and one precalc IRmap rendered at about 3000px. I think the exterior are easier then interiors because of the direct sunlight, the smal irmap where not any problem . But it´s not smooth to handle 10GB of vrimg... The image was printed with 100dpi, 12x1,5 meter.

Regards August

[paulison]

i've also found strip rendering to be the best solution and its very easy to do compared to the region rendering method IMHO

30k pixels...damn!. thats really scary.

One issue you may have is the 2GB file limit but if you are on a 64bit operating system then you are fine. Id be worried about having enough ram to stitch the image together as well. Maybe as a precaution, do a 15k one as well

[dcullipher]

Yes you can run out of ram a paulison states. MAKE SURE you crank up the virtual memory. That way even if max runs out of real ram it will not crash.

[mdi]

Has anyone tried to render an image 30,000 pixels wide? I have a request to do so with a particularly complex scene, think stadium complexity and you are not too far off.

Any suggestions?

(Yes, I have explained viewable distance and print res etc etc)

Thanks!

why so large, even a 48 sheet need be no more than 15k wide?

but yes, strip rendering will do fine, you need to pre calculate the IR map 1st though,

[MikeHampton]

I've never had good luck with vray when it comes to rendering super high res images, even if the scene is relatively "simple". I've alway run into memory problems, crashes, extremely long render times, etc. Anything above 3000 pixels I cross my fingers.. and anything over 6,000 and I don't even try to use vray with. Irregardless of weither I am using DR or not. And don't even think about using displacement at high resolutions!! Although 64 bit may help some of these problems.

I've recently had to render an image out at somewhere around 62,000 wide. :O I think with 32bit max it won't let you even try to render anything out bigger than 32,000 or so.

And I think that we had problems even at 32,000. So I believe what we ended up doing is rendering it at 16,000 wide (about 1/4 the final resolution) and using a fractal program to increase the resolution to 32,000 then fractaled it again to 64,000 (seems to work better doing it twice than doing it all at once). End result was that most people aren't going to be able to tell it wasn't nativaly rendered at that high of a resolution.

This was all done with the max scanline renderer using split scan lines. And even at 16,000 pixels, I think our machines had a hard time stiching the scans together. We had to do it manually in photoshop. Once it was fractaled up to full resolution.. the final image wouldn't even fit on a DVD.

My advice if you are going to try to render something that large in Vray is to make sure you only have to render the final ONCE. With the max scan line our scene only took about 30 seconds to render at 800x600.. and at 16,000xwhatever it only took a couple of hours or so. Thus when we had to make changes and revisions to it numorous times even AFTER the "final" rendering.. we knew we could re-render it in just a couple of hours. Even if we could have rendering it in Vray.. I don't want to think about how many hours/days it would have taken to render, then we wouldn't have been able to make the requested changes that always come.

Secondly.. be aware that each time you double the resolution you should be able to decrease your Min-rate and Max-rate on your irradiance map by 1 and still end up with the same rendering. So if for example your min rate at 800x600 is -4 and your max rate is -3 and you are happy with the results, and you increase your resolution to 25,600x19,200, you should be able to set your min-rate to -9 and your max rate to -8 get the same result. Although I've never tried this with anything that large.

Our image didn't look as good as it would have with Vray.. but like I said.. I shy away from using Vray with anything that large because of render times/memory problems. There definatly seems to be an expontial increase in render time and possible memory problem crashes as the resolution increases.

[dlparisi]

62,000? Please do tell why you needed it rendered at that insane of resoltution. What kind of map resolutions did you have to support this level of detail? Surely at this resolution your maps started to degrade and you would start to see individual pixels, no?

[MikeHampton]

Yea... crazy huh?

I've done SOME stuff for billboards before, and although I'm no expert.. because they are viewed at such long distances (several hundred feet).. If I remember correctly, the images are printed at VERY low DPI resolution (like 10dpi-20dpi or so). So even a 60 foot long billboard doesn't have to be over 14,000 or so pixels. Still a very large image.. but not quite to insane levels yet.

In this case.. this was for a lifesize mural printed on a wallcovering that was to cover the entire wall (including doors, door frames, etc.) It was to give the illusion of an extension to the room. This would be something that people may view from just a couple feet away. The overall size was 30 some feet by 18 feet. The company that prints the custom wallcovering requested an image at 150DPI. That seemed insane to me.. I wondered if they could have utilized the image at 100DPI or even 50DPI.. but I didn't have enough time to investiage this with them. So we just had to deliver what they requested. Which in the end, we were only capable of rendered at 1/4 the requested resolution and then increased using a fractal image program. And this is with the max scan line renderer on a relatively simple scene. I had to put the kabosh on using vray on this project right from the beginning because I knew we would run into rendering problems.

I would agree that if we were using maps that were only 2000x2000 or even way less.. not knowing how are they going to look when rendered out at such a large size? It actually turned out just fine. I believe this had more to do with that it's not like we had a 500x500 map of something that needed to be stretched out to 62,000 pixels. Most maps only covered a small portion of the overall image and were tiled. So a 500x500 map.. in the final image.. may not have been increased to more than 2000-3000 pixels. I'm sure if you look close enough and focus on just one map.. it's a little blurry.. it's just not noticalbe when looking at the entire mural or even just a part of it.

I'm curious though as to what other people have been able to do with Vray at these higher resolutions. Has anyone been able to render anything above 30,000 Or even above 10,000? And how did you do it? What was the render times? Are you using 64 bit (and how much ram)?

[EricCamper]

Nice...I think I would politley tell my client he doesnt need it that BIG. But I heard Size doesn't matter. Not that I have a problem or anything...I just make sure, there is never anything to scale with in the house.

[dlparisi]

So you didn't render a 62000 pixel image? It ended up something like 13500 right (1/4 size). To me this sounds more than adequate. Good story though.

[MikeHampton]

Yea.. if at all possible.. I try to give a full res to a client request, even if I think it's ridiculous.

However.. if due to workload, or deadlines, or just physically impossible for me to render at that resolution, I've always rendered it at the highest I could.. and just increase the resolution in photoshop or using fractals, and I have never had one complaint.

I always find it's easier to do that than try to explain why you can't render something at a certain resolution, and even easier still than trying to explain to them why they wouldn't even need it at that resolution.

As long as they think they are getting that requested XXX DPI, everyone always seems happy. Of course you couldn't take a 100x100 postage stamp and just increase the resolution to some insane amount, but if you are only increasing it 2 to 4 times.. like I said, for what we do, never had a complaint yet.