rendering time using a proxy vs actual object

[mitviz]

am not sure but i was asked about this by a student and i ran a test, it seems using proxies increase the render times, i ran a test to see and so far the proxy scene rendered in 5m 14.8 s and the same scene before proxy conversion 4m 43.2 secs, just need to confirm this is normal, i did it with 3 scenes so far and same behavior but just with trees.

[Neilg]

Normal. They use less/save memory because instead of pre loading all the geometry before rendering starts they can stream it from disk - which is slightly slower, but means that 20gb of mesh data repeated hundreds of times can be rendered on a 16gb machine.

Instance each of those trees around a thousand times and redo the test.

[mitviz]

ok just about to leave my friends pc so we both are here now on his pc running the tests, with the ordinary objects duplicated 1000 times i get a rendering time of 7m 8.7 s and the proxy duplicated 1000 times its 7m 53.5s and we had one more file open and a few other things we couldnt close yet and ram usage seems to be similar if not the same so idk, maybe later on my home pc i will see what is different but we both have the same cpu and motherboard etc so i guess it should be similar

[crazy homeless guy]

Proxies are about more than just rendering. They improve the performance of the viewport 10 fold and keep the file size to a smaller footprint.

[mitviz]

Proxies are about more than just rendering. They improve the performance of the viewport 10 fold and keep the file size to a smaller footprint.

yes, that part we know, we were just focussing on render times, using vray for awhile sometimes someone will ask you out of the blue something simple as this about proxies which makes you think and then eventually you go back to test it, and for sure i use it extensively to keep down filesize and better fps when working but always just used them never really wondering about the render times and its impact but the difference isnt major so i guess its no biggie

[glorybound]

My understanding is proxies will be slower, however, use less memory.

[Zdravko.Keremidchiev]

with the ordinary objects duplicated 1000 times i get a rendering time of 7m 8.7 s and the proxy duplicated 1000 times its 7m 53.5s

The purpose of the VRayProxy files is not about rendering time but instead saving memory and viewport performance when dealing with huge scenes.

[super gnu]

and ram usage seems to be similar if not the same so idk

i believe the proxy system will always use as much ram as it can, since this reduces the slowdown due to streaming stuff from disk. thats why unless you are maxing out your dynamic memory limit, you will see little difference between proxies and raw geometry.

also, instancing uses relatively little ram, wether its proxies or not.

i would also note that (unless i am mistaken) when using the progressive sampler, the whole proxy is always loaded (with the bucket renderer its easy to load only the piece of geometry that is in the current bucket, but progressive does the whole image at the same time)

if true this means you get no memory benefit from proxies with progressive..

i know this is definitely the case with vray RT, which loads all the proxies, in full, before rendering starts.


in these days of workstations with tons of ram, i tend to use proxies much less, sine they do render a touch slower, and also you lose the ease of editing. (although this has changes somewhat with the "show full mesh" option)

i will always keep stuff as pure instances until the scene starts getting heavy, and then go through swapping to proxies to keep ram usage, and scene load/save times sensible. for the viewports, "display as box" or hiding stuff works fine for normal meshes.

unless its a scene that i know will be unbearably massive from the outset, in which case i start with proxies and keep things as minimal as possible.


i can safely say though.. back in the 2gb ram days.. proxies were the most amazing thing ever when they came out.

[mitviz]

@super gnu, i find myself also using proxies just for very large scenes also and leave the geometry usually as displayed as box for viewport performance, the only issue i find is that when opening large scenes and not using proxies it takes a tad longer because the file is bigger ofcoarse, i maybe wrong and its scene specific sometimes but i also use proxies for that reason. Also here is a screenshot for the two files i did the test with, the proxies only file was much smaller indeed