Self Illumination

[Ravendark]

Hi there,

 

I'm wondering if anyone may be able to help with this problem i am having. I appreciate the subject of self illumination has been discussed on previous threads but after reading them, i still don't appear to be able to rectify the problem.

 

I have attached two images of the scene i am working on. Up in the roof there are four strip lights or rather objects i want to emit light. The first image has these strips with a plain grey material. The second i have applied a

A&D material with Glow in the Surface slot of basic shaders.

 

I have also tried lume here. Additionly i have tried both of these shaders in the Additional Light/Self Illumination slot and still got the same results.

 

After changing a million numbers and settings, mental ray has once again fried my brain, so i was hoping someone may be able to help!

[Ravendark]

Hi Brian,

 

A few more details would be helpful wouldn't they?!

 

I'm using Max 9 with mental ray.

 

I have a daylight system as the only light source at the moment. Using final gather and global illumination.

 

The scene is a car showroom which is brightly lit. I will be adding some more lights later on underneath the mezz level. For now, i am just trying to achieve a soft illumination on the ceiling from these strip lights, which will eventually have a cowl underneath making them uplighters. I just can't seem to get rid of the blotchy effect.

 

Ta

[Justin Hunt]

If you are going the self illumination route than drop an output shader into the SI. The output value controls the brightness of the light. FG must be used to emit light.

 

I agree with Brian that with such a brightly light space, the overall imact of the strip lights will be miminal

 

JHV

[Ravendark]

Thanks for your comments chaps,

 

Yes, i agree with what you are saying about the actual effect of these lights on such a sunny day and may not bother having these lights on at all.

 

The problem with that though is, that this scene is supposed to be in England. Sun of that strength, as you all probably know, is not something we have here!!! Wishful thinking on my part!!!

 

So, assuming i turned down the overall lighting, i would still have this problem.

 

Justin, i have tried output shader in the Additional Lighting/Self Illumination slot, same result. Is that what you meant?

 

I put the first image up to show that my Global Illumination and Final Gather settings are giving me a smooth enough render. So it is all down to this material.

 

Do i need to (if at all possible) increase the amount/ radius of photons of my self illuminating object?

 

I'm beginning to think this is something MR can't do too well, i wonder if there is a plugin?

[Ravendark]

As noted you are asking for it to give man made light fixtures the same energy values as the Sun

 

I not too sure i understand this.

 

I am not worried about physical accuracy of the lighting really, the scene isn't about realism but is showing fibrous plaster board. It's all rock n roll here!!!

 

Here is a pic which illustrates the kind of thing i am trying to acheive. Perhaps i should have just asked, "how do i do this..."?!!!!!

[Ravendark]

Area lights it is!!!! Looking much better now

 

Cheers

[Dave Buckley]

you could try without the GI and just keep the final gather, or if you've got the time and the patience, you could wait for Max 2008, i hear there are some great features that have been added that will help greatly with your solution when working with MR and self illuminated objects : p

[Tommy Burns]

You probably have long solved this already but just in case you might have overlooked this. Are your normals on the planes pointing the right way if not you have to flip down to face downwards. Then using the method of output shader you will see them as lights but they won't illuminate whats around them. I believe though that they are putting this function into Max 2008. That will be a huge benefit to me.

 

Hope this helps!!!