Confused about render times

Pook

I'm hoping someone can help me speed things up - render times are getting frustrating for me!

Whilst I've been ok rendering single figures on without a background (I did a lot of just messing around), I'm now trying to render something with skydome/landscape and so on. I'll admit, I've not got the best computer any more, but I'm getting render times which are a little on the... long side. 

The image I'm rendering now has the following in it:

Around the campfire

Night sky

Karyanna (and some clothing and skinning and stuff)

Persephone Hair

And then a small extra light for the fire itself. Nothing majorly complex in amongst this lot, so I thought it would render pretty quickly. I've not amended any shaders or materials (I'll attempt that later once I've got my head around it.)

First attempt using Iray gave me a plain black screen. I suspect parts of the render are not set up for Iray, so I'm fine with that. So I switch to 3delight, and hit render... and wait... and wait.... and wait.... Here I am, the next morening, 12hrs 46 mins into the render, and it's only 9% complete.

Admittedly my PC is not the greatest (i7 2600k @ 3.4Ghz, 20GB PC1600 DDR3, R9 380) and yet it shouldn't be this slow. Can anyone suggest what I should be looking at to try and speed things up please?

cjmarsh

In the advanced render settings have you enabled your GPU to help out with the rendering? Did you change the settings of the renderer at all from the default?

Pook

I can't see anywhere to get the GPU to help with the rendering. The settings I've got are as follows:
Progressive Rendering: On (Off is about the same for speed)

Buckets: Horizontal - Bucketsize 8

Sampling: Max Raytrace depth 12, Pixel Samples/Shadow Samples: 64

Gain/Gamma/Shading - 1.00

Dimensions: 1200x1449

Constrain Proportions (Global): On

Render type: Still - New window

 

GPU details:

Current OpenGL Version:
4.5.13431 Compatibility Profile Context 16.150.2111.0

OpenGL Provider:
ATI Technologies Inc.

Hardware:
AMD Radeon (TM) R9 380 Series

Features: 

MultiTexturing
Supported

Shadow Map
Supported

Hardware Antialiasing
Supported

OpenGL Shading Language
Supported

Pixel Buffer
Supported

Pixel Buffer Size
Not Enabled

Maximum Number of Lights
8

Number of Texture Units
8

Maximum Texture Size
16384 x 16384

cjmarsh

The advanced settings are in a little tab at the top of the window.

Pook

The only options I have in there are for Motion Blur and Render to RIB, both of which are disabled.

cjmarsh

Ah, I bet it's because the card is AMD and Nvidia doesn't support the GPU acceleration for that, sorry. Do any of your items have displacement maps on them? And is the render quality still 1?

Pook

I'm not sure if anything does have a displacement map on it - to be honest, I'm still at the "load everything in with settings at default and click go" stage of wrapping my head around it all. 

I do think I've found the culprit though - seems like if I turn off the sky dome the render times drop considerably - even swapping out the Night Sky sky dome I was using and replace it with something else it gives me a much faster render.

cjmarsh

Maybe the Skydome resolution was too high. There's some good free ones here if you need to replace it with something, just use the big HDR file in the download.

Pook

Thanks a lot for all your help :) I'll go have a poke around later on and see if I can get a better night sky to run with the image. I'm still getting used to Daz3D having spent all my time with Poser and some of it is a little more complex than I expected!

tl155180

Pook, I definitely think that having an AMD card is holding you back somewhat because it means you have to do cpu-only rendering in Iray, but theres a couple of things that might speed it up a little.

In the Render Settings -> Editor tab go to Optimization and under "Instancing Optimization" select Speed from the list rather than Memory.

Also, in Render Settings -> Advanced try checking the box that says "OptiX Prime Acceleration".

I suspect though that the main problem, in Iray at least, is using a nightsky skydome. Iray does not play well with skydomes unless you know all the particular workarounds for managing them. A skydome in Iray will basically block out all of your environmental light from the Iray dome itself meaning that all you have left to play with is the additional lights you add into the scene. Those lights will then not only have to illuminate your character, but also the entire interior of the skydome as well, which becomes very render-intensive. The good news is that you can do away with the skydome and just use the Iray dome instead, with the time set to night to make it dark. That should render a lot quicker.

This all just applies to Iray, if you want to give that a try again, because I don't do 3DL rendering anymore.

KA1

3Delight rendering doesn't use gpu acceleration so with that selected you won't have the option. I assume you're still in 3Dl as you have the motion blur option that I Ray doesn't have.

prixat

With Intel processors, 3Delight prefers much larger bucket sizes, try 128 or even 256.

I expect that Iray without a GPU is always going to be slower than 3Delight on your system.

jestmart

I have found the amount of memory your system has is the deciding factor in bucket size, the lower the memory the lower the bucket size.  You your raytrace depth and samples are far too large, 4 for raytrace and pixel samples and 16 for shadow samples are more than adequate for most scenes.

3anson

Max Raytrace is WAY to high, 2 bounces are plenty, unless you want.need a lot of reflection. even then, 3 or 4 is usually plenty.

here are a couple of settings that are fine for good quality renders.

Ray Trace Depth :- 2

Pixel Samples :- 32 + 32

Shadow Samples :- 32

Shading Rate:-  0.050

Pixel Filtering:- Sinc,  6 + 6

These are Adam001's  " Insane Quality" settings

 

Ray Trace Depth :- 2

Pixel Samples :- 12 + 12

Shadow Samples :- 32

Shading Rate:-  0.10

Pixel Filtering:- Sinc,  6 + 6

These are Adam001's " Very High Quality " settings.

Either set will give you crisp, sharp, high quality renders. The " Very High Quality " settings are more than adequate for about 90% of renders.

The " Insane Quality " settings will increase rendertime exponentially, quite often with no noticeable 'improvement' in visual quality.

The other  thing is do not use ' Progressive' mode for final renders. it has a bug( still, AFAIK ) that switches the Pixel Filter to 'Box', which does not give such a clean render as 'Sinc'

Also, check the skin shader on the character texture you are using to see if it has SSS enabled, this gives much more realistic skins, but at a slight cost in rendertime.

Check the 'Shading Rate' of the skin textures in the 'Surfaces Tab' , quite often it can be set to 4 or lower. changing  it to 8, will speed up the render, without noticeably compromising final quality.

one other thing, when rendering in 3Delight, make sure you do not have any Iray shader based textures in use, as 3Delight cannot read them properly, and from personal testing, i have found it can increase rendertime tremendously.

hope this helps :))