problem when rendering large image

[DT18]

HI!

 

I need your help!

I'm trying to render my scene, (using vray 1.5) it's a billboard that will be 80" x 40 " aprox

so I want to make my render 8500 x 4250 px. I read it was allright, is it??

 

The problem is that I got an error when rendering. I also tried saving as a vrimg file, but just when the render is about to start I got the classic: "

 

An error has been produced and the application will now close......would you like to save?"

 

I'm really lost what should I do? WHat si the vray set up recommended for this cases?

[Peter M. Gruhn]

Other people will help you with rendering large images.

 

My question is how far away will the image be viewed from? Do you really need 100 dpi?

[Horhe]

Search the CGA forum for answers first.

This has been discussed before, try this:

http://www.cgarchitect.com/vb/search.php?searchid=1311134

[bjeves]

we have recently had this problem and we got around it by running the irradiance map and light cache passes first. then render the final image through the network as strips. brake it into about 40-50 strips.

[DT18]

Thanks for the answers

 

Other people will help you with rendering large images.

 

My question is how far away will the image be viewed from? Do you really need 100 dpi?

 

The billboard will be next to the road, entering a city. It will be seen maybe from 5 meters away, and considering the cars will be going no more than 60 km/h.

 

we have recently had this problem and we got around it by running the irradiance map and light cache passes first. then render the final image through the network as strips. brake it into about 40-50 strips.

 

I found somewhere in the forum about running the irradiance and light cache first, and I'm doing that. In about 8 hours that first step is about to finish (20 hours total)...

Can anyone help me how to configure through the network as strips, as I never had done this before???? I'm not quite sure how do I have to set it up

 

 

 

By the way, the full image 1000x500 took about 30min. I have a vraysisplacementmod for the grass, would it be a good idea to take it off for the big size?

 

Another question, I have a P4 3ghz and 3 gigs dual core of RAM, how do I know if I'm using 100% of ram and how to make it work at 100%... according to render dialog in the memory used group it says P:1235M approx

[Eric Sosa]

I think hat the main problem is your pc configuration. you migth need a much bígger machine to takle those renders....besides running in 64 bits and NOT including the displacement. there are several ways to make an ok looking grass for animations and big areas.

 

gook luck & saludos

[chiquito]

for respect to other readers, I write in English (perdon daros) As for the time its taking: I believe you could give a try to a render farm outside, youll get the image in about 4 hours. Take out the displacement on gras, post produce it in photoshop, have a smal render, take it to reall size, and just work on grass there, you then attach real size grass onto big render. calculate te money you spend on "frozzen" machines.

As for the issue with large rendering, look around the forums, I have seen before some solution that it renders small buckets each time, doing calculations on small pieces rather than all image.

Good luck"

share results if you come up with something handy1

[SgWRX]

i have rendered images at 3600x1800 and had them made into 96"x48" signs and they looked pretty decent from 20-30ft away. the sign company who made the signs said his print system can interpolate up, but i don't know the details of it.

[colimfx]

i have rendered images at 3600x1800 and had them made into 96"x48" signs and they looked pretty decent from 20-30ft away. the sign company who made the signs said his print system can interpolate up, but i don't know the details of it.

 

 

Hi SgWRX,

 

May i know what is the dpi you set for your rendering ?

[SgWRX]

well. that turns out to be about 37.5dpi, or rather pixels per inch. so on the sign, 1 inch would contain 37.5 image pixels strictly speaking. you can resize and image by interpolation get get the pixels smaller so you get a smoother image, more blurry. i'm not sure what type of program the printer used to resize the ones i sent him. photoshop or some other programs like genuine fractals can do that. qimage is a printing program i use and it has a fairly advanced interpolation routine in it. then you can play with sharpening masks to define edges more by adding contrast and kind of trick your eye into thinking the image is sharper than it is. interpolation or resizing, tries to add to a picture what isn't there. it can give a good guess but it can't really give a sharp edge.

 

what it comes down is, render an image at 2400x1200 or 2400x1800 then pull that into a program and print out a full-sized crop at 72ppi on an 8x10 sheet of paper or 13x19 sheet. then hang that up on the wall and start walking away from it. it'll start to look smoother the further you get away from.

 

i think, and i'm not sure on this, but i think billboards for highways and such need only be around 72ppi. i use ppi vs. dpi b/c dpi came about in printing terms to more or less describe how many dots of ink the printer could use in printing out a 1 inch area. when you think about it, at 72ppi each pixel of a rendered image is 1/72th of an inch, so that's pretty small. some printers needed to be able to print smaller than that b/c it had to mix colors in that small space in order to get the right color of that image pixel. so...

[SgWRX]

here's another way to look at it. a computer monitor is about 96ppi. so my monitor is about 19.5inches wide which comes out to be 1872pixels wide. my native res on this monitor is actually 1920. so anyway, i grabbed an image that was 4096 pixels wide, a photograph with a 6.3mp camera onto which i put a rendered image. that rendered image was the same aspect ratio as the photo (4:3) and it rendered at 4096 pixels wide.

 

so anyway, i put that image up on my monitor in full screen mode. at 72ppi it said the image would print out at about 56" wide. well, on my monitor at 100% zoom, it looks pretty good. when you figure the 96ppi that a monitor typically is, to me 100% zoomed image is about 41.75 inches wide total if i had a monitor that wide, i'd see the full width of the image displayed one-to-one on my screen (about that because there's a difference between the 72ppi and the 96ppi)

 

so now, i zoomed in to 200% size and yep, i can start to see individual blocks (the enlarged pixels). i'd have to have a monitor that was now 83.5 inches wide to see the whole thing edge-to-edge. but, yes you can see the pixels. so now to to 400% zoom and then you're talking a 167" wide monitor to see it edge-to-edge, but when i zoom in to 400% wow, tons of pixels are visible. but if i walk away from the monitor to say about 10 feet, it doesn't look so bad. kind of blurry but not bad. can't really see jagged edges in lines that are of high contrast (white against a darker area).

 

so if i wanted the 167" wide image to look as sharp as it did when it was about 42" wide (100%zoom) then i'd have to render 400% larger than 4096 pixels wide. in other words, if i wanted it to be as sharp and detailed with my eyeballs 33" away then that'd be a huge render.

[DT18]

Thanks for all the answers.

 

Since I didn't do any job like this before, and this is all new what I can say is that after reading in some threads and some intuition what I did is:

 

I calculated the irradiance map and saved it (as I read somewhere) and since I don't know how to use backburner or sth for what you call a farm render (I suppose) I rendered my scene 8000 x 4000 with the "crop" render and then I joined all the pieces in photoshop.

I got very good results really, so this job is finished now and someone would be printing the billboard now.

 

By the way, where can I read something about backburner and make a queue with a number of renders to render automatically.

 

Thanks a lot for your help!

 

for respect to other readers, I write in English (perdon daros)

 

Of course chiquito we have to write in English (mas que entendido)

[Eric Sosa]

here's another way to look at it. a computer monitor is about 96ppi. so my monitor is about 19.5inches wide which comes out to be 1872pixels wide. my native res on this monitor is actually 1920. so anyway, i grabbed an image that was 4096 pixels wide, a photograph with a 6.3mp camera onto which i put a rendered image. that rendered image was the same aspect ratio as the photo (4:3) and it rendered at 4096 pixels wide.

 

so anyway, i put that image up on my monitor in full screen mode. at 72ppi it said the image would print out at about 56" wide. well, on my monitor at 100% zoom, it looks pretty good. when you figure the 96ppi that a monitor typically is, to me 100% zoomed image is about 41.75 inches wide total if i had a monitor that wide, i'd see the full width of the image displayed one-to-one on my screen (about that because there's a difference between the 72ppi and the 96ppi)

 

so now, i zoomed in to 200% size and yep, i can start to see individual blocks (the enlarged pixels). i'd have to have a monitor that was now 83.5 inches wide to see the whole thing edge-to-edge. but, yes you can see the pixels. so now to to 400% zoom and then you're talking a 167" wide monitor to see it edge-to-edge, but when i zoom in to 400% wow, tons of pixels are visible. but if i walk away from the monitor to say about 10 feet, it doesn't look so bad. kind of blurry but not bad. can't really see jagged edges in lines that are of high contrast (white against a darker area).

 

so if i wanted the 167" wide image to look as sharp as it did when it was about 42" wide (100%zoom) then i'd have to render 400% larger than 4096 pixels wide. in other words, if i wanted it to be as sharp and detailed with my eyeballs 33" away then that'd be a huge render.

thx steve.

 

good option, although I have never tried, it sounds like a way to do those realy huge renders....withough "rendering" to such big size.