Render speeds in Carrara, light sets, etc.

ModernWizard

Hey everyone. I've had some success with Carrara, but I've been working with World Gardens Maze, one dressed G2F, and the default lights, and I can't get a decent render out of it in less than 60 minutes. This makes me sad because I am extremely impatient.

What tricks to you use to reduce render times in Carrara? Are there like speed rendering tips? Are there particular light sets that you use or something?

I know that, in Daz Studio, you can avoid adding lights to a scene and get a basic, flat render [OpenGL?] fairly quickly. Does Carrara have something similar? I'm ultimately pursuing a stylized, slightly toony style, so flatness isn't a problem.

I'd be making crappy Carrara renders all over the place if I could figure out how to do them in <60 minutes!

--MW

Headwax

Hi ModernWizard, it's hard to get a quick render with Howie Farkes's work. (edited for correctness thanks Wendy).. - so it's not a good place to start - could be tranlucency in the leaves, replicators, soft shadows? Or a combination of these.

Most scenes sold for Carrara are sold for their beauty, not their render speed.

For lighting an outdoor scene, here's a good place to start for speed.

• Drop in a distant light, make it 130 percent and yellow - this is your sun.
• The next few lights mimick the sky colour - this fills in the shadows with the sky colour - so mimicks light reflected from the sky dome. Via:
• Duplicate the first distant light, change the angle a bit and make the light a  blue colour  and ( say) 12 percent luminance -
• untick shadows on this light or reduce the percentage - say 25 percent
• Duplicate this new one - probably the angle will change slightly - if it doesnt just move the angle - the idea is to fill in the shadow areas made by your first distant light (the pretend sun)
• Do this another three times - always changing the angle a little to get complete coverage.
• Group these blue lights - call them "Sky"
• Then duplicate this group - call the new one 'ground.'
• Make them point upward.
• These new ones will mimick light reflected from the ground so make them the colour of the ground.
• Make them (say) 8 percent luminance and untick shadows otherwise your ground plane will block them.

This a great setup because it avoids soft shadows (these slow you down) but mimicks them reasonably well.

It renders much faster than other complicated Carrara lights.

You will need to tweak how bright the lights are and their shadows - depending on the scene.

PhilW and others suggest Gamma set at 2.2 - this is great for indoor scenes but for me washes out exterior scenes.

Do your test renders on fast antialising and the final renders on 'good' antialising.

 

others will chime in I hope

 

 

 

 

 

 

 

 

 

 

 

 

chickenman

ModernWizard said:

Hey everyone. I've had some success with Carrara, but I've been working with World Gardens Maze, one dressed G2F, and the default lights, and I can't get a decent render out of it in less than 60 minutes. This makes me sad because I am extremely impatient.

What tricks to you use to reduce render times in Carrara? Are there like speed rendering tips? Are there particular light sets that you use or something?

I know that, in Daz Studio, you can avoid adding lights to a scene and get a basic, flat render [OpenGL?] fairly quickly. Does Carrara have something similar? I'm ultimately pursuing a stylized, slightly toony style, so flatness isn't a problem.

I'd be making crappy Carrara renders all over the place if I could figure out how to do them in <60 minutes!

--MW

What render settings are you using as a few of them can really slow things down.

Also if you set the render bucket size to the smallest (16) then heach CPU thread can move on to a different part of the scene faster and it does make a difference.

Improved Ray tracing will slow you down to a crawl. Sky light and indirect light can have an effect but not as great as the ray tracing. 

Wait until Dart or PhilW chime in they are better at it than I am.

WendyLuvsCatz

you mean Howie Farkes work, slight mix up there Headwax 

yeah I modify the heck out of his scenes as do animations 

as is it's impossible 

that maze a particularly heavy one

WendyLuvsCatz

and if lighting accuracy is unimportant, delete all the lights including the fake GI dome, up the ambient to 100%

maybe add a bulb dragged to the camera as a headlamp with the shadows unticked.

I have done this for very fast toony renders.

if patient you can also go through the plants one by one in the modeling tab and put the smoothing down to 2

Headwax

the3Digit wroteth

you mean Howie Farkes work, slight mix up there Headwax 

picky picky :)

Headwax

writing below in secret lemon juice

still dunno how he got his name through the Daz 1984 swat team. It's just as good as Wombats: eats, roots and leaves.

heh

WendyLuvsCatz

a quick go no lights ambient 100 (50 may be better) all trees and shrubs at 2 and all SSS and translucency removed

and lower settings in render for raytrace filter etc

16 secs a frame

WendyLuvsCatz

is not a good example but gives an idea what is doable

 

Dartanbeck

Light domes are very customizable to get faster renders or the other way around, too.

In my EnvironKits, for example, I've given them a default of 88 lights in the Artificial GI light dome because that is a good amount of lights to achieve natuarally soft shadows without using "Soft Shadows" in the light's effects tab.

For my own personal use, I don't need that soft a shadow. So I go into the light dome replicator and change the minimum distance from 280 to 980, which yields 11 lights instead of 88. Keep in mind that I also use other techniques to make this work for my scenes, but the renders are incredibly faster - because I also turn off the soft shadows onthe sun light, which is On by default.

So for Howie's light domes (Fake GI), I've done a similar thing, reducing the number of lights to around 11 to 14, and then, since he's using spot lights, I increase the angle to 45 and give the angle a falloff of around 15 to 30. Much faster, still effective.

In both of the above examples, we'll need to increase the brightness of the replicated lights to make up for being less of them - or make up for the loss of light in other ways.

Like Head Wax was saying, too, is that Howies uses Translucency on his leaves, which makes them look absolutely stunning, but really adds to the render time. Just find all leaf shaders and change translucency to "None". You'll notice a big difference in the shadows, so you may wish to use a bit of Ambience in the Scene settings to counter the lack of translucency. That or add a distant light or three that aim upwards without casting shadows, kept to a low brightness and add a touch of color.

Not nearly as precise, but much faster.

jrm21

I the furthest you will get from being an expert on the topic, but I can offer a few tips that haven't been mentioned yet.

- Depending on the look you want, you can get some vey nice lighting by using an HDR image as the background and turning on "Skylight" in the render room (but not indirect light). Using indirect light can render a nice image, but it can increase render time substantially.

- Using a blurred image (as opposed to one with much detail) for the above step will cut down on render time

- for any lights in your scene that cast shadows, use a shadow buffer setting instead of raytraced shadows

- lower the "distance" value on scene lights. You usually don't need the default value (is it 400 ft?). 

- As mentioned by others, complex scenes such as the Farkes stuff are difficult to render. Much going on. There are ways to cut render time there, all at the cost of quality.

- be careful what effects you use. Things like motion blur and Depth of Field can increase render times.

 

Using primarily these steps, I can often get render times to about 15second/frames on a 720p output size. That can work on animations. For stills, you generally need higher quality. 

Another trick I have heard of (but don't personally use) it to render in layers. Especially useful in animations. If the camera doesn't move, for example, render only the background. Then render mid and forground elements separately. Combine in post. 

 

ModernWizard

Thanks for your tips everyone. Of course I would have to pick the complex scenes with a lot going on as my favorite. :p

Anyway, the advice that people have given me shows me what is possible and suggests some avenues I could go in. In particular...

headwax -- thanks for the tip on the alternative lighting setup, as well as the note that HowieFarkes' stuff is pretty system-heavy.

chickenman -- there are so many render settings that I'm a little daunted, even after reading the manual. Thanks for the highlight on which settings can be memory hogs.

3ddigit -- thanks for doing a test render with some adjusted settings on the World Gardens Maze.

Dartanbeck -- thanks for the info on soft shadows and ways to produce a similar effect in less time.

jrm21 -- thanks for the input on HDR as a light source.

I solely render stills at about 1070 x 715, with unrealistic lighting and DOF, like the attached. EDIT: Okay, apparently I can't attach files at the moment. >:[

--MW

Dartanbeck

Well... it's not your fault. Howie's scenes are just freaking amazing! So we can't help but want tio use them a LOT!!! LOL

I do many other things to help speed them up using this thought process:

Howies' scenes are provided as "Complete Scenes"

So when I want to use them, but instead of seeing the whole thing from above or far away, I'm actually "in" the scene more, I'll start by inserting a cube and growing it in scale to fully encompass my shot. It helps to make it semi-transparent.

Now in my Director's camera, I select the cube and hit 0 (zero) to center on it, then xoom way out from it.

Then I start selecting parts that are furthest away from that cube, which Howie often hides from being seen in 3d view, so we often have to check that to see them.

Some of these far away details have literally thousands of trees on them. Carrara does a pretty decent job of still being quick with things the camera cannot 'see', but when they are using setting that can really slow a render... getting rid of them can really make a dramatic difference.

We can simply make things invisible if we want, but I always keep the original file unchanged, so it never bothers me to simply delete what I don't need, then Edit > Remove Unused masters (all three options).

When doing this, sometimes I then decide to bite the bullet (on render time) and set his translucency back to original - it looks so good!

I wonder if Howie still has his notes his used to have on the old ArtZone pages. He had very extensive study reports on his products with very real advice on changes that he would experiment with to increase render speed, complete with illustrations showing the visual trade-offs. They were not only incredibly informative, but highly entertaining to read as well. The old Daz3d installer's ReadMe file had links to these pages, which was how I found them - but they're gone now.  Major Bummer.

Howie wasn't alone. Many of us had some rather extensive reports within those pages. To have such a thing disappear was a real bummer.

Headwax

great to see you working in Carrara!

here's some more tips:

I do a lot of stuff in post that would take too long to render - eg fog, light flare, soft shadows etc

when you render, render out some layer passes eg:

shadow

fragment coverage

material diffuse

object

depth

you can use some of these to help isolate your image elements for post work - eg object pass and frag coverage pass help you with this

use depth for a layer mask in post to simulate dof (stay away from infinte planes as they will stuff a depth pass up)

they all fall down with  alpha maps eg hair - so you need to do some hand work in t his regard if you use them as selection masks

if you render as PNG or TIFF you wont have to untick 'embedded' for all those passes

also if you name your file before rendering it will save you a lot of time

 

in Carrara keep your lighting simple , and build up from there 

keep in mind that you can also isolate the objects that a light will effect

 

I render 12 inch by 14 inch miniumum for printing at 300 dpi - so render speed is what I aim for too - life is short after all

and while the next image is rendering you can be working up the last in post ;)

 

3DAGE

you can also render complex scenes, such as howies stuff,. then use that as a Backdrop,.

or ,...if you insert a Spherical camera, and create a 360 degree render, ...then you can add it as a scene Background.

then you can add your figures, light those,  and render.  ...it should take seconds, or a couple of minutes.

if you're only rendering stills,  think about rendering your figures with an alpha background, then compositing those into a rendered out background image, in a 2D image editor,. .