www.kraytracing.com

Hello. It seems Kray is best suited the scenes that have some component of external lighting. I was planning on using Kray to render scenes on TV and Film Sets that dont use exterior lighting. Is there a tutorial somewhere that describes the best way of setting up a scene using ONLY standard lights and NO daylight?

I have tried to get Kray to render an existing LW 10.1 scene that already has numerous lights but none render. Am I doing something totally newbie-ish?

Thanks. Phil

I suspect You need to render without Sun and Physky so night scenes or closed rooms.
Actually is the most easiest think in renders.
Why I say easiest? because for that I use only physical sources of light. It make very clean photon map and no big problems.
Possibilities of use lights in scene are huge so this is just small example.

Now rules:
1. Do not stretch too much Area Light - it make "brake" of continuum (it is no bug , Physical lights are emulated in Kray and to clean this effect you need raise up min/max for Area Lights quality for example 2/4 or 3/4 - it will make longer time render so better is to put two shorter Area Lights instance of one.) Example on the right side of scene. Good example from ceiling lamps where I put two of them
2. Do not put Area Lights near objects (wall) it will make noise near lights (it is no bug). Problem comes from strong photons. Good idea is too move light a bit farther - example light on the right scene.
3. Do not use Spot Lights - better IES
4. Do not use lumi lights with high luminescence! It affect strong "hot photons" (it is no bug) and this is normal. Render engine doesn`t know which light is Sun and which one is bulb. This is all the time problem in all kind of renders engines. Why I use Physical Lights. It is correction tool for this problem in Kray...but it works randomly and is difficult to use.
5. More light - more problems. Problem is smaller with Physical Lights (actually my record is 220 Physical Lights - Auditorium scene http://www.kraytracing.com/joomla/phpbb ... &mode=view ...so is not that bad). More Physical Lights - longer time render because grows amount of raytracing calculations.
6. If you MUST use lumi lights (small lamps over stair steps) then make maximum 100-200% luminescence level. More power - more splotches.
7. Sometimes after import Items from lws scene Lights render wrong photon map...I have no idea why (bug in LW?) So better create it from beginning or switch them for while to another type then render and again back to original.
8. All the time make PhotonEstimate/Precomputed and PhotonEstimate/GlobalUnfiltered. It will show you information about photons: the position and density. It takes while.

All these problem will be fix in K3

Good luck!

Well, that was an excellent response - and fast too! May Newtek know on your door and offer you a billion dollars. You're worth it....

I still can't work out why none of my lights are illuminating. I have four overhead area lights to add a level of light and other area lights for typical uplighting, but none are switched on. Why?

filmdesigner wrote:I still can't work out why none of my lights are illuminating. I have four overhead area lights to add a level of light and other area lights for typical uplighting, but none are switched on. Why?

I remind: all the problem with render or/and attach scene problem.
I am not sure You talk about "to see" Area Light or general problem with no photons from them

As always, really useful post Janusz, thank you!
Sometimes Lumi lights cannot be avoided, like when you do a LCD screen . How do you deal with it?

khan973 wrote:As always, really useful post Janusz, thank you!
Sometimes Lumi lights cannot be avoided, like when you do a LCD screen . How do you deal with it?

only one solution:
- lumi 100% for screen (it can be also image if is turned on) that small level will produce "weak" photons which will not have any influence for general situation with photon map in scene
- Area Light with blue/pink color - not strong! it is no Lighthouse but enough to get nice bluish light near model. It must be done manually but You know how make fast preview
- it will be nice to add on screen material (this lumi image) Ray Tracing shader from Kray - but is buggy, and making it as second layer only for screen is a bit messy (layer switched to ray tracing works perfect) So no photons at all from this material. But I think 100% lumi is not big deal and it can be in scene.

In K3 will be less problems with lumi lights.

Hello Janusz.

I would send you the scene file I am working on but not through the public forum as it is confidential (clients!).

I still cant get the Lightwave lights to work in the Kray render. I have no idea why..... I have noted Kray chooses one light and ignores the others. Can this be switched off so Kray sees the other lights?

Cheers, Phil

filmdesigner wrote:Hello Janusz.

I would send you the scene file I am working on but not through the public forum as it is confidential (clients!).

I still cant get the Lightwave lights to work in the Kray render. I have no idea why..... I have noted Kray chooses one light and ignores the others. Can this be switched off so Kray sees the other lights?

Cheers, Phil

I never had that problems with lights.
Prepare light version of scene and send me:
janusz.biela@gmail.com

I suspect you missed something in Kray (maybe save photon map you mixed with load) or you use some strange Nodes?

janusz think this setup and scene need to in depo scene - share it so the user foundit fast!!

Hello Janusz.

I have a file for you to check. I am still having trouble getting Kray to use the Lightwave lights. I have no idea why. I must say the glowing surfaces are making a beautiful light, but I need to produce TV studio lighting and need spotlights.

The scene I have here is a preliminary and only partially lit. I thought I should bask your advice before I proceed. I have sent you an email.

Phil

Ok problem was easy to find in your scene. I sent you answer by mail.

Hello Janusz.

Thank you for playing with the scene I sent. Your renders are looking good - but!- when I open your scene all the lights switch off! AGAIN!!! I am finding this a real pain. I opened your amended scene in LIghtwave and your lights didnt work. I replaced your lights exactly and the they rendered in Lightwave but NOT in Kray.

Is it possible I have a corrupted version of Kray or something?

FYI: I opened the scene, removed all the lights except the "one you have to have" (switched off) and rendered a new scene. It looks okay but very dark. If I add a single light over the lounge area it wont render.... It turned the light up to 100% and still nothing. Its weird.

Another thing. You mentioned I shouldnt "Mix my Linear settings between Kray and Lightwave". Can you explain? Should both LW and Kray be using a Linear space?