Rendering Paper and Cardboard for Speed

[moleytron]

Hey Everyone

So I'm rendering some scenes of houses and streets that are all made of paper and cardboard. I'm using a PBR workflow with paper textures out of substance designer.

The renders look great, but I started to think I might be able to render quicker and I was hoping for some advice on the following.

I'm using a single coronasun light and am using path tracing for the secondary solver as it's an exterior screen.

Because everything in the scene is matte paper, there is nothing reflective or very shiny is there anything I could turn off or turn down to speed up my rendering?

I'm using pretty much default settings at the moment.

Thanks in advance for any help or suggestions.

Moleytron

[fellazb]

Would be nice to see what the rendertimes are now actually

[moleytron]

Hi fellazb

Thanks for the reply. I'll run out some tests tomorrow and post the here.

[moleytron]

Hi Everyone

So I've run out a test render. Which you can see below. Any advice on how I could optimise this would be greatly appreciated.

The Render
Size 1920 x 1080px
64,000 polys
No DoF
Geometry Motion Blur
I'm using two 2K maps for all the textures
Single Coronasun light
Tone mapping
Secondary Solver - Pass tracing
5 passes
50% Denoise
Everything else is default settings
Render time 2min 48 sec


My Specs

Windows 10
Intel Core -i7 6700HQ CPU @ 2.60 GHZ
12GB DDR Ram

[FrostKiwi]

There is quite some interior, as seen by looking into the buildings, so use UHD Cache for secondary, it will still use PT+PT for outside, but UHD Cache for inside.
Unless it's some weird motionblur: it seems that the roof and the stairs on of the building the right have Z-dapth fighting. (Two surfaces, perfectly intersecting each other)
This can cause Splotches and random noise, as it becomes random, which surface a ray hits. Zdepth fighting has to be always avoided.

Lastly 5 passes 50% Denoise is quite the thing. If you gonna use such low render settings, don't use MotionBlur, as it will look aweful and 5 passes motion blur, will never look right. You can always try post processed motionblur, like ReelSmartMotionBlur for after effects. (infact, after effects even has a built in feature)

[moleytron]

Hi SairesArt

Yep  you're right. I'm definitely gonna bump up the passes to get a nice result on the motion blur. Thanks for all your advice.

There are some intersecting artefacts going on, I'll be cleaning those up as I go, it's all very much a work in progress at the moment.

Do you think I'm better off sticking with default settings? Do you think there is anything to my hunch that because it's all paper I may be able to alter some settings to optimise?

Many thanks

Moleytron

[maru]

Use UHD Cache - that's for sure.

As to GI - you could set LSM to 1 (the direct lighting is simple), and increase GIvsAA to get faster/better GI, BUT that would cause mblur to look worse in a given time.

OTOH to make mblur look better in the same time, you should lower GIvsAA.

...so if mblur is more important to you I would suggest lowering LSM to 1, and GIvsAA to 8.

...if you decide to disable mblur - LSM 1 and GIvsAA 32.

You could also try introducing some extra bias - e.g. lowering MSI to 10.

[moleytron]

Thanks Maru!

So after thinking about it some I realised by far the quickest way to render was to bake my textures!
So most of the scene is a static environment, with nothing reflective. Ideally suited to baking.
This gives the lovely and subtle shading of Corona sunlight with near real-time rendering once the bake is loaded back into the scanline renderer.

Obviously, this isn't necessarily the solution I was looking for when I posed the question, but it will work nicely for my project.

Thanks everybody for your help.

Moley

[moleytron]

On a related point.....

Is there a way to have baked items render quickly in Corona?

So in the scanline render if I have a standard material, load a diffuse texture and push self-illumination up to 100%, it renders super quick and just displays the mapped texture, no shadow or further shading are applied, it can however cast shadows, be motion blurred and be reflected in other surfaces.

Is there a good equivalent for this technique in Corona?

Thanks

Moley

[maru]

There is this string option:
bool shading.enable = false
and "render only masks" checkbox in scene settings. I am however not sure if it works with RTT, and I cannot check it right now.

[romullus]

On a related point.....

Is there a way to have baked items render quickly in Corona?

So in the scanline render if I have a standard material, load a diffuse texture and push self-illumination up to 100%, it renders super quick and just displays the mapped texture, no shadow or further shading are applied, it can however cast shadows, be motion blurred and be reflected in other surfaces.

Is there a good equivalent for this technique in Corona?

Thanks

Moley

Once you bake everything with Corona, you then can plug textures into standard materials and render finals with scanline. Why render with Corona if you don't need GI anymore?

[moleytron]

Yeah, mostly for convenience, so as not to have to switch renderers with different files and or state sets.

[Jpjapers]

It might not be relevant but if you modelled your paper buildings as if they were actual miniature model size (small) and set it up like a model using a lamp as a main light source using a standard corona light you might end up with a result that looks alot more paper-like and model scale.

I did this style this week for an architectural model and it worked a treat! Autodesk actually featured it on their instagram today which was nice of them! :D
It took about 20 minutes for 35 passes plus denoising time.

[moleytron]

Awesome work. Looks great!