WIP: Reducing render times

[pdwyer]

I know quite a lot is written about reducing render times already, especially with regards to different lighting setups but I wanted to get some specific advice on this.

The latest model I was working on was a air rifle and after rendering it Fletch's advice from a few months ago rang in my ears about having a scene for it rather than just have the item floating in space or sitting on a baord yet again... like this:

VSR10-02.jpg (64.14 KiB) Viewed 10916 times

So, thinking about a scene, I wanted to put a lot of my old models in too, even if they were just background images for the scene so I came up with "the Garage".

The two images below are 10hrs and 23hrs rendering time each on easy-10 and it's not really a matter of just de-noising them, some of the details are still not as clear as I'd like.

Garage-03-final.jpg (202.59 KiB) Viewed 10919 times

Garage-04-final.jpg (194.05 KiB) Viewed 10920 times

The light bulb is done differently in each, the first one has the light emitting surface painted on the bulb which I know translates into a lot of light emitting faces so for the second on I got a small triangular pyramid (4 sides) shape and put in inside a real milky glass bulb. These end up being just as slow as eachother. There is another bulb off screen over head.

I want to use naked light bulbs as I like that effect and look and I can't find a faster way to set up a rig that still looks good but I'd like to get my render times down to about 7-10 hours if possible for a clear pic. The ourside sky seems to be somewhat slow to render through the frosted glass too. biased renders really bog down on that window

Any advice on this?

As for the content, I need more 'stuff' like tools on the walls etc still but I'd like to get this lighting/render time issues worked out.

[Fletch]

Fantastic modeling.
I love the scene, and dig how you put the sword in "the shop".

Render times are all about materials, polys, and lighting. So, you have those two working against you here. If you put a light object inside of a translucent materials and light your scene, the render time will be quite slow. Blurry materials, and especially blurry refractions (blurry glass, blurry metals) will slow down any rendering significantly.

If you want the bare clear bulb look, why not create an image of a filament, and place that inside the bulb, and let it be the light emitter. You can supplement the light from that with a spot light inside the bulb as well (be sure to set the size of the pointlight to equal the size of the filament). Then try the thin glass shell materials in the Twilight_Architectural material library.

You can also supplement the light in the space by an off-camera single rectangular plane as a light emitting source, it can be soft and subtle, just behaving as a fill light, but providing some direct unfiltered light to the scene. Direct light always renders more quickly, no matter the render setting.

[pdwyer]

Thanks Fletch,

I'm doing some more benchmarks with some of what you have mentioned, it's hard to benchmark with the unbiased render settings though becuase sometime a pass will take longer after an change is made to improve the speed but the amount of denoising happening is increased per pass ... I think I'll benchmark just with the biased and hope that translates somewhat

[Fletch]

Subject: Lighting: "transparency" of the lampshade

[pdwyer]

but, but, but .... you cheated! you did it in post pro!

That kind of throws down the gauntlet I think, there has to be a way to do this 'for real'

I'll be back!

[Fletch]

Well, post-pro is not cheating, every frame of the LOTR and Star Wars trilogy contain post-pro. Post pro is part of CG.

The glow of the filament is not post-processed, it's a light emitter.
The "flare" that you see from a camera lens is difficult to create with Twilight/Kerkythea because of the design of the camera in the render engine. So post-pro is the fastest/simple solution. Sure there could be other ways, I'm sure there's a creative way to make it without resorting to post-pro, but the time it takes to find that solution is far greater than to just make it glow in post-pro.

[pdwyer]

thanks for the tips... getting there!

Garage-04-03-2-postpro.jpg (408.32 KiB) Viewed 10626 times

[pdwyer]

Done! Render time was 12 hours, not too bad for the res.

The light is a point light made slightly larger than the bulb and then the bulb's outer material was a light emitter set to fake.

Garage-06-02-post pro 2 .jpg (406.42 KiB) Viewed 10510 times

[pdwyer]

I always wanted to do one of these... sorry for the gawdy colour

merge3.jpg (343.25 KiB) Viewed 10477 times

[pdwyer]

I'll probably get banned for spam soon

merge5.jpg (332.49 KiB) Viewed 10471 times