Atrium (Mental Ray)

[aflack]

Hi,

 

This is my first image using 3D Studio Max, I used Menal Ray because I found it quite easy to use. This isn't my design I used an image from Visualizationmasters.com and changed it a bit so I didn't have to model so much.

 

Any advice on how to make it better and using what techniques would be appreciated, I have quite a limited knowledge of Max at the moment. I used the glare shader to make the light coming through the roof glow, but I was kind of hoping that the direct sunlight on the floor would glow as well, but it doesn't seem to, so any advice on how to make that happen would be great.

 

Thanks

[Woody79]

overall it looks ace! it could do woth some more modelling detail, increase the reflection and blur the floor. Also add some colour with maybe prints or some coloured walls, detailed light fitments etc.

the devil is in the detail.

[jtiscareno]

Very good start. Lighting looks great!

 

Only comment is that wood paneling looks flat.

[aflack]

Thanks for your reply's your right about the wood looking flat, I'll give it a little bump and make it a little reflective. I'll bring up the reflection on the floor as well. I'll post my results!

[shopkeeper]

Looks great so far.

 

Can you be as kind to post settings and render time please.

 

Thanks

[aflack]

Seeing as this is my first image I wouldn't take too much from these settings as I don't really know what I am doing to be honest.

 

Render time was about 7 hours, that was for a 1600x1200 image.

 

Shooting 10000 global illumination particles and 15000 final gathering particles. I never set the radius of the particles to anything just left it as the default.

 

One Mental Ray Spot Light with shadows set to Mental Ray Shadow Map. And under the Mental Ray Indirect Illumination Rollout for the light I increased the energy to 18000000.

 

I have no idea whether these settings are right but they seemed to work, maybe someone with a better understanding of mental ray could give me a little guidance.

 

Thanks

[joske]

well : the 'global illumination particles' you are reffering to are called photons

the idea is to have the entire scene covered with them slightly overlapping each other to get a nice average calculation.

 

using bigger radius will allow you to use less photons,but will give less detail

smaller radius will need more photons, but also has longer rendertimes...

 

try to use only GI and photons at first, (no final gathering) so you can see the 'photons' in your scene (kinda like a light bulp shining on a wall)

this way you can set up the 'size vs overlapping' to be optimal (enough detail, but as big as possible to reduce rendertimes)

i always use around 50-80 cm (make sure your units and system units are set up correct to know what your doing)

 

than slap on only a slight fgathering to even out the result and have better detailed shadow around sharp edges and cracks in your scene someting between 3000-6000 should do it, otherwise your photons are not set up ok)

 

the energy level is way to big, so i suspect someting's not setup ok with your untis...

energy level should be 50.000-200.000 not more, try to lower de decay from 2 to something like 1.5 to compensate if your scene is to dark

 

to have beter result with the glare on the floor, try to make the material from the floor whiter, or increase the glare settings in the material editor (but then the whole scene will be more 'glared' so that might not be what you're going for...)

 

also the leather on the seats is a bit to shiny, real leather has a more matte feel to it (but now i'm picking on details here

 

succes with it

phil

[aflack]

Any idea how to sort out my units. At the moment I have it set to milimeters so 1 unit = 1 milimeter. Is this not correct?

 

Thanks

[joske]

1 unit = 1 milimeter is fine. but then your photons for instance should be 500 -800 instead of 50-80

(500 mm = 50 cm)

 

i'm not sure that you will have to do the energy level x10 also...

i allways use 1 unit = 1 cm and then my energy level never exceeds 200.000

 

but do make sure your system units are the same as your units!

otherwise your seeing the units in cm or mm, but still working in inches (default max setting)

i'm not sure this could cause problems for sure, but just for making it easier for your own sake i would put them the same.

 

you will get the same results with a bad unit setup... eventually... but if you wanna know what your doing, and want to have a decent kind of worklfow i would suggest this unit setup for all max purposes, not only for mental ray scenes.

 

cheers

phil

[aflack]

Thanks for your help, On the image I am doing at the moment I have set it up the same way by I am having to multiply the energy by 25000 to get the scene lit and then it looks really weird.

 

I have attached the image. I am using one MR Area Spot.

 

Also not sure if you can help me but is there a way to control Colour Bleeding in Mental Ray. i have used an Architectural Material but it gives you colour bleeding control but as you can see the orange still bleeds and the areas in shadow just look weird its like they kind of glow.

 

Thanks for your help!

[joske]

keep in mind that when your doing Gi light setup of a scene that you cannot light for instance a 'footballfield with a candle light'

 

so make sure your 2 main light sources (the sun and the sky) are strong enough to start with

 

for sun just use a spotlight

for sky use a series of omnis near the windows (for interiors)

and/or a skylight for exteriors

 

you might also wanna put on the log exposure control, there you can specify the 'scale of the light vs the scene' (however this is just a kind of balance afterwards, in this case putting a log exp contr. probably wont do the trick, your scene should look almost fine without Log exp contr. also)

 

bounces and coulorbleed is a the hardest to control in Mray/max6 imexp

you only get one bounce and no standard material setting will give you more colour bleed...

here's a thread over at cgtalk about this issue :

 

http://www.cgtalk.com/showthread.php?s=&threadid=117519

 

i'm sure there are a few more threads overthere dealing with this, you could do a search easely for that...