www.kraytracing.com

Greetings,

I have been using Kray now for about 3 days. This is my first post. I have spent a good portion of these 3 days reading all the posts and learning from them. I'm trying to figure this thing out. So far I'm having good luck with it but would like to ask for help from you seasoned users. I'm using a project that I originally did in lightscape last year. (Triumph brewing in Philadelphia PA USA) I have imported all the geometry into LW and did some basic texturing, nothing fancy. Just trying to get optimized rendering times with similar speed / quality as I currently get out of lightscape.

Questions:
1. I have rendered this image image with these settings:
Link to image: http://www.pechara.com/kray/triumph.jpg
Link to settings: http://www.pechara.com/kray/settings.jpg
The render time is 3 hours 45 min. (using a saved gi file) Is there any way to make it go faster and still retain the quality or even make it better quality.? I?m still trying to grasp the concept... any pointers or settings i should change?

2. What is a easy and quick setting for the AA that does not take forever to process and gives quick acceptable results. Out of all the settings, I?m finding the "sampling" tab the hardest to understand. Perhaps because it takes so long to test different settings.

Its a bit confusing at first with new software and any help would be greatly appreciated. Im looking forward to speaking with you guys on here. Kray seems like a software that is worth incorporating into my studio. Just need to make sure I learn how to drive it!

I found standard level2 Mitchell AA to work quite well. This is not FSAA.
There's something odd going on with those linear lights under the counter. Way too grainy.

Also, did you turn ambient light off? It looks a bit washed out.

Render to HDR and reload the image back into LW in the image editor, then add an HDR expose filter to do some exposure correction and get the better_bloom plugin from flay.com, that will help with the highlights.

Thanks for the AA tip. Its working well. I found a scaling problem in my scene: correcting it now. That should greatly improve the performance.

Light question: it seems i have to set my lights (area or spot) as low as 5% just so the image does not wash out... is this a symptom of something im doing wrong?

Hi there,

1. 3Mio photons are alot, you might want to lower them to aroun 1 Mio to 1,5 Mio and raise N to maybe 4000 - 6000 and lower Prechache blur to 100%
2. Min. FG Rays could be higher. Try 250 - 400.
3. Set Max. distance to 3000%. Angle tollerance can be set to higher values like 40° in most cases.
4. I would set AA to 2 or 3 and Mitechell filter.
5. Set Luminosity to compute as indirect and Are Light recurse to 2 - 4.
6. Raise the octree depth, if Kray gives a low octree warning.

Cheers, Florian

Thank you for the help. I fixed my scale problem and re-set up the scene with the new settings that you guys gave me. Some of them made the whole image look weird so i modified them some more. Now i have strange phantom light problem. See the image here:

http://www.pechara.com/kray/kray_trimph-01.jpg

There seems to be a strong light source in the space above. This was not there on previous test renderings and now i cant get it to go away. Any ideas?

Also, I'm still getting relatively long rendering times. Much faster than regular lightwave, but still too long to be able to do a reasonable animation. Do I expect too much? How do I modify these settings so i get a reasonable render time? ( a 720x480 is taking 1 hour. http://www.pechara.com/kray/settings2.jpg

In lightscape, once the processing is done (+/- 5 hours) the same frame can be kicked out in 45 sec.

BTW, here are the original lighscape renderings:
http://www.pechara.com/html/architectur ... umph01.htm

I appreciate any help. although im not as convinced as i was before that this software will replace lightscape in my office. Perhaps if i can get it to render faster! It is great software anyway and a great improvement for lightwave.

Hi there,
what computer are you rendering this on?
Did you turn of ambient light? How high is your ray recursion limit? Try 6 to 8 there.

here are some more tipps:
FG Tab:
Try spatial tollerance 0.1, distance Max 3000% and angle tollerance 20% to 30%

Quality Tab:
Recurse min - max 2 4
blurrin rays 100 - 1000

You could also try to use luminous polys instead of area- and linear lights. If you do, you need to create a seperate part for every lumi light in modeler.

Cheers, Florian

Florian,

Thank you for your help so far. I'm running Lightwave 7.5D on AMD 64x2 Dual core 5200+ /w 2GB ram. I do not have any ambient light (0%) My ray recursion is @ 24. This must be too much! I will try 8.

Spot lights are giving me some weird results so I'm using point lights above in the circular tube lights hanging over the tables lights. Area lights are above the bar, upstairs with the tanks, on the bar wall and below the bar. 8 spot lights and 54 small area lights.

I will try your settings now and report on the results. On the lumi polys: Can I just make a Square polygon and load it into the scene multiple times and place it into the locations of were the light fixtures are? All the light fixtures are single object that are cloned multiple times and placed into position in layout.

Again, thanks for your interest in my progress.

pechara wrote: Can I just make a Square polygon and load it into the scene multiple times and place it into the locations of were the light fixtures are?

Yes, you can do that. But make sure to assign the lumi poly to a part in modeler.
Also all the bottles in the back could cause a very long rendertime, especially compined with a ray recursion limit of 24. Lowering it will be good. You might even be able to turn of transparency on the wine bottles to gain more speed. The transparency is hardly noticeable.

Florian