How to reduce my rendering time?

George_VRA

I have DAZ3D running on a PC with 8 GB RAM, dual core processor and an NVIDIA 8800 (i know shitty card but i am planning to change it)

When i try to render an image (16:9) with Iray Nvidia it could take up to 40 hours for a single pic.

Is there any way to reduce my rendering time (besides upgrading my pc with a quadcore and a new graphics card which i am planning to in the near future) without loosing quality?


Is there something i can do in my rendering options that could help? Or i am stuck with 2 days of rendering with each pic?

Richard Haseltine

You don't say how big the image is, but I would suspect that with only 8GB of RAM there's a lot of swapping to disc going on. If so reducing the size of the textures may help a lot - but that does depend on the final output size.

PA_ThePhilosopher

George,

There are some things to look out for, but generally speaking, you can't reduce your render times much without a hardware change. But there are a few things which seem to help, including reducing texture size, as well as decimating geometry with high polygon count. 

Another big resource hog is smoothing. Any clothing with smoothing turned on will sometimes slow things to a crawl. It took me a long time to figure this out. 

-P

Roman_K2

PA_ThePhilosopher said:

 Another big resource hog is smoothing.

Oh-oh!

I find that anything in 16:9 that is 2,222 pixels wide say is usable on the web and in many applications, while not taking too long to render. 3 to 5 hours or overnight *maybe*, but nothing like 40 hours. 3,333 pixels doesn't change things too much (while giving a more HQ render) but I suspect that with 4,444 and 5,555 (these values are easy to type, heh) the render time starts to climb rapidly.

Is smoothing the clothing the same as taking the sharp edges off of models? Here's the DAZ playing card set, part of a 4 to 5 hour render of the ashtray and some cards. I'd really like to smooth out those pointy corners that you often get... in this example I've tried to cut the deck a bit with postwork, to make it more realistic. If you look carefully (red arrow) the corner that *I* put in by hand [edit] is nice and smooth, but the original DAZ rendered corners have little points on them, above and directly below the red arrow. They're not smooth.

Rodrij

I find that minimizing reflections and geometry like crevices where light bounces a lot reduces rendering time. Having everything well lit reduces rendering time and using hdr rendering lights is the fastest. The fastest way to render that I found is to render the background and actors seperately and then puting the background and actors together later. The only time it won't work is if the shadows are cast on walls but you can also just render that one wall with the actors. When rendering with the character by itself you can set it to render shadows in render settings so it will show up when putting actors and background together, you can also make visible any objects the shadow lands on when rendering actors. 

Not rendering related but does affect time to render is reducing the time it takes to load assets. If you keep a render window open it will skip the loading time before rendering. For example once you have every asset on the scene start the render, it will start loading objects and once it starts rendering ,.ie iteration count, stop the rendering but don't close that window. You can then render again once you are ready to render but you won't have to wait for objects to load. You will take up more system ram doing this, so it might not work if you have too little ram. It is worht doing, since bigger scenes can take as long as 12-18 minutes to load into ram before rendering even starts. With the render window open objects area already loaded and save minutes rendering each scene.