Illumination problems...

[Ky Lane]

Hi guys,

 

Ive got an internal scene basically setup, and have my lighting rig around it. Theyre a bunch of 0.2 direct lights with no shadows setup to hit from all directions...see image.

 

Now, for some reason, the walls are illuminating different to the ceiling? They both have the same material applied, the ceiling just has a vraydisplacementmod applied to it for the ceiling panels.

 

Any ideas?

[jvlive]

I dont understand why you're light rig is scanline-like while youre using vray....

[Ky Lane]

Well theyre just setup to generally illuminate the internal scene...theyve always worked before...just with this it seems the ceiling is playing up..

[Arnold Sher]

okay... if you prefer using standard lights with vray, what you are doing is not the way to go... I would advise to put an omni light in the centre of the room slightly yellowish do not turn shadows on. Play with attenuation with "start" being a third and "end" just outside of your interior walls. Switch ambient on. That will give you general lighting with no shadows on with rather a soft effect (suitable for vray and scalnine), although this is rather old school but with still use it for internal big spaces if we are really pressed for time. Than apply spot lights at your discretion like you would usually do in order get shadows underneath desks, chairs etc... Hope you like it...good luck

[Ky Lane]

okay... if you prefer using standard lights with vray, what you are doing is not the way to go... I would advise to put an omni light in the centre of the room slightly yellowish do not turn shadows on. Play with attenuation with "start" being a third and "end" just outside of your interior walls. Switch ambient on. That will give you general lighting with no shadows on with rather a soft effect (suitable for vray and scalnine), although this is rather old school but with still use it for internal big spaces if we are really pressed for time. Than apply spot lights at your discretion like you would usually do in order get shadows underneath desks, chairs etc... Hope you like it...good luck

 

Thanks for the tips

 

What other lighting system WOULD you use other than standard lights?

[Arnold Sher]

photmetric lights is the way to go... comes with ies tab which basically means you can set up your lighting with true lux levels which is how it works in real world..

[Ky Lane]

OK. I probably need to do some tutorials. I use an array of Direct lights with no shadows to just generally illuminate a room, then use photometric lights etc to simulate the rest.

 

What Im producing is a large floorplan which is generally fluroscent tube lit. So I want to get a fairly bright general lighting thing going on, then use real lights inside to produce my shadows etc.

 

With the lighting rig, I can just up/down the general lighting to get the desired level of general illumin, then play with the real lights for realism.

[Justin Hunt]

Ky, are you going to do GI or Fakocity?

 

JHV

[Ky Lane]

The difference being?

 

I guess fakocity, for speed....maybe when Im finished Ill make up a GI rig, but I doubt Id get the results Ill need through lack of experience...

[Justin Hunt]

Basically, there are a few tricks you can play with Fakocity to get the GI look eg AO.

 

If you were to go with GI then dont bother with the rig, rather just place photometric lights in the light sources and Vray lights at the windows.

 

JHV

[Ky Lane]

That didnt make much sense, but thanks anyway

 

Well, the problem with this rig is, there are no windows. All internal fluroscent lighting (and a few halogens)...

[Justin Hunt]

Sorry I was being obtuse on purpose, every time I mention Ambient Occlusion I get shot down in flames;)

 

With Fakocity, unless you are going to use a whole bunch of soft, shadow mapped omni's it will be difficult to get the subtle soft shadows in the corners and junction where objects are sitting on the floor etc. AO with give you that. There are several methodes of use so you will have to experiment to find one that is best with Vray.

 

My personal favorite and easiest is using AO in the diffuse level slot of a Oren-neylar blinn shader, for each material.

 

Others are projecting the AO from and Omni to get the AO pass and compositing.

 

Both these methodes are based on MR workflow and as yet I havn't experimented with Vray.

 

As to the ceiling lighting what happens when you move the upward facing directional lights to be more vertical?

 

JHV