My first KRay render!

[Josamoto]

I'm new to Kray, so your patience is appreciated. Not sure if I should post my pic here or in the gallery, but here goes, coz I'm sort of asking for help as well.

The scene contains one area light near the centre of the room. About 9 other ambient point lights are also present with 2 area lights outside the shop simulating light coming from the city mall.

The render at a resolution of 630x360 too over 2 hours. I used the basic default Kray settings, Lightmap with 20000 rays. 800Fg rays and 3x3 grid anti-aliasing.

Is there any way I can speed up the render time without losing too much quality!

The light splotches between the back ceiling and wall are due to gaps in the geometry. That's been fixed and currently rendering.

Your help is much appreciated!

I also touched up the image in PS CS2 a bit. It was too dark and I cooled the colours down a bit as the scene seemed too red overall.

Kray looks cool! Why don't you guys alliance with Lightwave or Modo?

[jure]

First go into Photon estimate mode and turn up number of photons. 20.000 is too low. Try 500.000- 1million... Select "Global unfiltered" and render out a scene.

If there are enough photons then you can move on to "Precomputed" mode.

Tweak N and Precache distance to get smooth "Precomputed" render. Usualy N of 1000-2000 is enough.
Check this thread for how irradiance should look like http://www.kraytracing.com/forum/viewtopic.php?t=89.

Use "shared GI for all frames" with "save" mode so that Kray saves out precomputed irradiance data to file. You will use this in next step to save some time.

Now turn to Photon mapping with "Cache Irradiance" checked. Also swithc to Load for Shared GI.

Go to FG tab and play with settings. For testing use low FG values (min100 max 400). Play with Spatial tolerance and min-max distance to get nice spread of samples in scene.

When all is looking good you can turn up FG max (at the top of FG tab) to some high value like 2000 or more...

Render speed depends alot on correct FG settings... Hope this helps somewhat, also be sure to check Tutorial I made for v1.5. You'll find more usefull info there. http://www.kraytracing.com/forum/viewtopic.php?t=46

[Josamoto]

My rendertimes on the images where quite high, so this morning I set off with your tutorial, tweaking the values.

Me settings are as follows:
Photon mapping, Cache irradiance = on.
Use global Autophotons = on
Photons = 50000
N = 200

FG threshold = 0
Min rays = 100
Max rays = 400
Spatial tolerance = 0.4
B/D = 250%
Oversample = 50%

Stochastic antialiasing
Threshold = 0.5
Rays min = 100
Rays max = 400

Pre render 25%
(values not mentioned are on default)

...and here is the result.

[jure]

Looking good!
There seems to be enough photons in the room and irradiance is quite good also. Maybe you'd want to turn up the N value to smooth it out even more.

The FG settings can be improved though. I would turn up the oversample to 100%. This has been changed in 1.6 so the settings from the tutorial don't apply anymore. Before lower values than 100% improved FG but with 1.6 values over 100% produce denser FG.

You can try lower spatial tolearnce settings also, which will give you more details in shadows. You will probably need to turn up max rays though...

Also try Grid Ful screen AA, grid size 3. Turn Undersample to 16 or 32 and threshold to 0.0. This will make Kray render AA in one pass.

[Josamoto]

Thanks Jure! I will have to fly to Europe some day and buy you a beer!!!

I'll try your settings shortly, should be able to have an update tomorrow. I just feel the image needs a bit of warmth as well. But I could be mistaken.

Here is a render I did from the exterior of the book shop.

[jure]

Glad to see you're making nice progress!

I'd just suggest that you turn up outside lighting so that it's more bright. Right now it seems the lights are too weak.

cheers!