Newbie with Kray, first test, a couple questions.

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videodziner
Posts: 2
Joined: Fri May 20, 2016 4:08 pm

Newbie with Kray, first test, a couple questions.

Postby videodziner » Fri May 20, 2016 4:32 pm

Hello everyone,

I'm a long time LW user, and I've been tasked by my employers to try to raise our render quality to better compete with the Mental Ray studios around, so I'm evaluating Kray for Lightwave.

I been through a most of the video tutorials posted by JureKray, and I realize I probably have barely scratched the surface on using this software. I'm hoping you all can look at a render and answer a couple of quick questions.

On the Kray render, I really like the shading, but I'm wondering how to avoid the graininess on the ground. Also I'm seeing some ailiasing on the car roof roof and hood. The scene is lit with 2 luminous polygons.

My settings are:
GI resolution: 200 mm
Photon Preset: Custom, Photonmap
Global Photons 500000, emit
Power 2.0
Use Autophotons: On
Precache Distance: 50%
Precache Blur: 100%
Low, High, Steps,: Default settings
Final Gather: Medium
Sampling: Custom, Box, Filter Radium 0.1
Antialiasing: Grid, Full Screen: On, Rotate Grid: On
Grid Size: 4
Quality Preset: Uncached
Luminosity Model: Automatic, Level 100%
Plugins: Tonemap Blend: On, 1st Tonemap: Gamma 1.0, 2nd Tonemap: Exponential 2.2, exposure 1.0, Blending 50%

Besides pointing out where I should tweek my settings, any suggestions on sites and resources to better learn this software would be appreciated.

Thanks in advance,
Vid.
Slate Mustang_Kray 01.jpg

thomas
Posts: 401
Joined: Tue Aug 31, 2010 9:59 am

Re: Newbie with Kray, first test, a couple questions.

Postby thomas » Fri May 20, 2016 5:31 pm

Hi there and welcome to Kray!

You chose a great render engine, and after a couple of years development Kray 3 will be out soon, so expect a jump in render quality soon.

You turned off "cache irradiance" and that means better shadows, but with noise. Noise is noise, and there's only one way around this: letting it render longer, or at a higher resolution, to get less noise. The tricky part is that the gains you get become small as your rendertime become longer, and you NEVER get to zero noise. For example:

1 hour render gives "40 percent noise".
2 hour gives 20 percent noise.
4 hour gives 10 percent noise.
8 hour gives 5 percent noise.
16 hour gives 2.5 percent noise.
32 hour gives 1.25 percent noise.

So you see, in the end you wait longer and longer to get rid of the noise. If you want zero noise, you need to turn on "cache irradiance" again, but then your shadows become less realistic.

Kray 2 is about four year old technology I believe. Kray 3 will have vastly superior photon mapping that will allow you to get excellent, realistic contact shadows with no noise. In the meantime, learn Kray 2 to get up to speed!

A simple trick for less noise, and better anti-aliasing: many people keep the quality settings set to low, but render out at a very high resolution (like 6000 x 3000 pixels). At this size noise becomes a very delicate detail, like a soft film grain. You can then use Photoshop to de-noise a bit.


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