Help for High Resulution Picture

[Bennick]

Hi All

I am currently trying to make a picture with the resolution of 10000x2500 , detail-level=0.9 and OS-system = Windows 7 (64 bit) memory = 6Gb

but I do have some huge problem with the 4Gb limitations, and it keep crashing, I have tried to adjust detail-level, Max/min Threads and Size of Subdiv Cache.

Is there a method (Formula to calculate how much memory is need) to reduce the memory allocation, and except a lower performance (longer rendering-time), or is there other parameters that can be adjusted?


Best regards
Morten Bennick

[Tangled-Universe]

I don't know how soon the 64-bit version of TG2 will be released, but perhaps it's an idea to wait for it.

If you can't wait then there's a way of doing it by rendering it in crops.
You could render it in 4 crops, in this way for example:

crop #1
crop left = 0
crop right = 0.28

crop #2
crop left = 0.24
crop right = 0.52

crop #3
crop left = 0.48
crop right = 0.76

crop #4
crop left = 0.72
crop right = 1

With this setup all the crops have the same amount of overlap. This overlap is necessary to be able to remove GI-seams, which might and probably will occur. Though that depends on your scene of course.

Don't forget to use the ray detail region padding to allow terrain/objects outside the crop cast shadows/reflections into your crop-render.
I'm always a bit confused which setting to use, but I believe you need to use the "detail in crop" function.
You can set the value to 1 for example, which means that the shadows/reflections will be calculated 100% of the cropsize outside each size of the crop.
So with a 2500x2500 crop this will mean that shadows/reflections will be calculated in an area of 7500x7500 pixels.
You can imagine this is rendertime laborous, so a value of <1, 0.5 for example, might work as well and even faster.

Like I said again, it depends on your scene whether you need this really much. Perhaps you could post a smaller version of your image to show?

Cheers,
Martin

[nikita]

Are you aware of the fact that this resolution is already at the limit of what the human eye can see? Unless you are planning to physically build a 180° immersive panorama, this seems pretty big to me?

[Bennick]

Thanks for help, that might be a very good idea to crop the picture

Just for info, the picture is going to be used as a very wide poster!

Best regards

Morten Bennick

[domdib]

What is your intended physical poster size, as this will affect output resolution? If it's going to be *very* big, you can reduce resolution, as people will be standing further away from it.

[Bennick]

The width is 4m. We have tried to lower the resolution, but it didn't get the right result

/Morten Bennick

[leafspring]

Are you aware of the fact that this resolution is already at the limit of what the human eye can see?

If the rendered image is printed with 300 DPI, the 10k pixels result in a width of ~80 cm which isn't very large.

[nikita]

Yes, but there's usually no need to print a 80cm poster at 300dpi.
Assuming that you will stand at least 80cm away from the image, it'll only take up 30° of your fov. The eye can resolve structures to a size of about 1/60°. This means the poster only has to be 30 x 60 = 1800px wide when looked at from that distance.

Of course, this depends on what you're trying to do. When you want it to look perfect even from a small distance, e.g. when reproducing a painting or making a detailed panorama, then you indeed have to use up to 300dpi or whatever is enough.

All I'm saying is the following: Try not to render more pixels than the eye can see. Also, not more than whoever prints your posters can print.

[Oshyan]

If render time is not as much of an issue as running out of memory, then I would suggest using only 1 or 2 render threads, and only 50-100MB cache per thread. To do this set both min and max threads to e.g. 2. I would also suggest reducing detail to 0.75 unless you have done crop tests and determined for certain that detail 0.9 is necessary. Knowing your current GI and other settings, as well as scene details (e.g. how many populations and other objects and how big) would help optimize further. With a 64 bit OS you should be able to finish the render with properly tuned settings, but it will take a while.

- Oshyan