Lights contrast and GI, need help

[digitalx3d]

b-spline,
sorry, I wasn't too clear about that. Under the "secondary bounces" section>Direct Computation...."Depth" is what I was referring too. I believe this is the number of bounces each ray will take after the first bounce. Setting this lower will decrease the brightness in the corners somewhat.

As for your other question- I usually stay away from the color mapping because you can usually do it photoshop much faster. Compare the time it takes to render your scene 5 or 6 times (in order to get desired results) to the time it takes to use the Levels in pshop. 2 hours to 2 minutes??

John Pruden
Digital-X

[b-spline]

john, you're right about color-mapping, but I'm not able to do it in photoshop with levels. so I need to have a scene much illuminated, very clear and bright, but I don't want there are some burnt areas near to windows of light souces. and I need to use some object-light also, can you tell me something about these questions?
anyway thank again for your help!

[flipside]

Can you post a 3ds file of your scene? I can't open max 5 files...

Regards,

flipside

[digitalx3d]

b-spline, not exactly sure what you're asking, but I do think that working with self illuminated objects will cause you a lot of headaches. I've found it nearly impossible to get desirable results for anything other than accent cove lighting.

You're on the right track with experimenting with many different methods. Just crank down your quality settings so that your renders only take no more than 30 seconds. You can see the lighting effects quite well even if your image is antialiased very poorly.

So I guess I'd ditch the self-illuminated objects and use the color mapping, and figure out which types of lights will work best.

John P.

[b-spline]

hi flipside,
this is 3ds file: http://digilander.libero.it/tafkaand...p/scene3ds.zip

in these scene there are not self-illuminated object under the ceiling.

for John:
so you suggest me to ditch self-illuminated object, but use exponential color mapping. ok, I'm doing experiments in this way, and I've got some results, but... also for fake, I need to have under the ceiling some faked small spotlights. What kind of material can I give to it? because If use exponential color mapping, a very bright material becomes grey.
is this now my problem.
thank for yours replyes!

[digitalx3d]

I believe that with the color mapping you can make your bright areas brighter and your dark areas darker. Maybe try using color mapping only to make your dark areas darker. Do not make your bright areas darker.

Then if you have some recessed light fixtures in your ceiling...wait....hmmm....I think I need to clarify something. When I said "self-illuminated" objects, I was thinking of "geometry lights", created by using the Output map in the diffuse or self-illum slot. These actually generate light.

If you're only using the self-illumination to show a lightbulb that doesn't actually generate light, then i have to take back what I said! This is fine.

Post some progress. Let's have a look.

John P.

[flipside]

Hi, I did a test.
No lights in the scene, only vray skylight.
This is the result:



Is this what you want? What exactly is your problem and what are you trying to do with the scene? What should it look like, a sunny day?

Regards,

flipside

[b-spline]

yea flipside. I need something like this, a sunny day, more brightness.
anyway can you send me your scene? tafkaandre@hotmail.com

for john,
I've to light a scene like this.
so I start tryng these examples:

A/B) 1 vraylight (mult.3.3) + environment skylight (mult.1.4)
Indirect illum 1st bounces 1.0 / 2nd bounces 0.5
Direct computation - Sub.1/Depth 3


C/D) 1 vraylight (mult.10) + environment skylight (mult.1.4)
Indirect illum 1st bounces 1.0 / 2nd bounces 0.5
Direct computation - Sub.1/Depth 3


E) 2 vraylight (mult.3) + environment skylight (mult.1.4)
Indirect illum 1st bounces 1.0 / 2nd bounces 0.8
Direct computation - Sub.1/Depth 7


my main problem is that I have to get an uniform illumination.
so if I increase light multiplier, the object near to vray light
becames too bright. but If I use exponential color mapping, image
becames so blurred.
How can I do?

[digitalx3d]

Are you trying to light the scene from outdoor light only??? Why not place some spot lights under those ceiling fixtures? That would make your lighting more uniform. You render times are pretty quick, so it seems you could stand to add in another light or two.

The images really look good, so I would say they should definitely be acceptable to most clients. Are you just messing with the lighting now for your own enjoyment?

John P.

[b-spline]

Yes I do John, I'm trying to light the scene just from outdoor.
Client likes the images, but He wants a scene more lighten and uniform.
And then my head is very hard, so now I want to light it good.
But It seems that the only way to get it is to put other lights, may be under ceiling, and render time will enormously increase!
I'll made other attempts, then I show you results,
Thank you for attention

[flipside]

Here's a screenshot of my settings:




Also the materials have vraywrapper to set generate GI to 1.25 (you can also do this per object instead of per material)

I didn't do anything else, all the rest is default (I added one light to the scene that is turned off, so max's default lighting is turned of)

I can't send the file because I use the demo, and all settings reset whan I save.

[b-spline]

thank you flipside, your tecnique is very interesting

[yog]

I think you might be making things harder on yourself than you need to.

In the office I work my desk is about 3.5 meters from the window, and even this close I need to use artifficial light in order to get sufficient illumination.
The human eye is very adapt at balancing varying degrees of illumination and making the light appear more balanced but at the same time making you aware of shadowed areas. This is not the case with traditional cameras (or even virtual world cameras).
If you were to take an actual photograph of the type of room you have shown lit only with natural exterior light then you would see a great difference between the light and dark areas, near the windows some areas would be overblown, whilst the areas near the back of the shop would almost be obscurred in dimness.
A friend of mine who designed and built his own home had a proffesional architectural photographer come around to take some pictures for a magazine. Even though the photographer wanted the interior to look as though it was lit only with external light, she used a surprisingly high number of interior fill lights and bounce cards. The final photographs looked how the human eye "percieved" a well lit internal space with no internal lighting.

If you struggle with just 3D external lighting sources you are more likely to end up with something that approaches what a camera would record rather than how the human eye would percieve it.

[b-spline]

Hi yog, you're perfectly right, infact I tried to insert other lights into the scene, and results are much better:



now illumination is cleaner, though render time increased!

[Psy]

can you show what you changed, or a screenshot of ur workscreen so us lowly users can have a see at how did that?