Night scene

[marko04]

Hi,

Last time I posted my interior WIP, I was overwhelmed with the level and quality of support from here. It really helped me to solve problems I had there.

I am currently working on a project (for quite some time now) of some sort of warehouse/office building.
I have virtually no experience with exterior and no experience with night shots at all.
Thus, I got myself into trouble.
First, my render times are sky high.
My original 2000*1414 image was rendered for 30 hours. I am using core2duo 2GHz with 2GB of RAM. Is this normal considering the fact that scene has ~ 200 IES lights and ~ 100 vray lights?

Second, my client would like me to resolve the lighting solution.

I managed to get it this far.

http://i305.photobucket.com/albums/n...nder222WEB.jpgNow, he doesn't like the light reflectors on the roof, and he would like me to do that part more discreetly.

The roof is made of some kind of semitransparent material.
He would like me to put the light inside the object, so that mesh will glow from inside. I presume that best method would be to put the vray 2 sided mtl and to move the reflectors inside, so that they can light the mesh.
Is this correct approach? I would appreciate any suggestion regarding this issue...

Also, comments and critique regarding overall work are more than welcome.

Thank you

P.S. The statue in front is scaled replica of Chicago Picasso, on clients demand. At first I created something I thought more appropriate, but I had to change that.

[d.sign]

Forget all about IES lights and Vray lights inside the object...
No need for all of that, not a single one if you ask me, not to say 100... for start at least...
You can add some IES lights after you done with overall setup, just to make some accents and add more directional light where you need it...
By directional light I mean on the real light source that can be controlled in Vray by number of subdivisions...
First, you take your scene and set up environment light
You can use some HDRI file if you have a sunset one or something like that... or you just set the color of environment to dark blue, or use gradient map or something like that
That is to be very low intensity... just to ensure that building is visible.
Than you solve the artificial light simulation by simply using luminous geometry.
It could be visible as real light sources and emit light and GI (put the Vray light material inside of Vray mtl override). You can turn off visibility in object parameters or set the amount of GI intensity that object emits by using Vray object properties panel (right click to access both of the menus...)
For your luminous semi transparent box roof you simply create one box and give the sides some thickness. Than apply the gradient ramp map to make it vary in color a bit (look at illustrations bellow...) and set the opacity of material to some middle value and add some reflection to the material.
Inside that box you add another one, a bit smaller and put the light material on it, with rather low intensity
(all the lightmaterial intensities should be adjusted to overall exposure of the scene or Vray camera), also map it with gradient, box type and set UV type to face
Try to play with it a bit...
After you done with rendering, even if you are not too happy, there is still a lot to do with it.
Postwork in Photoshop is very important and it can give you lot of options if you use filters and layers, add diffuse glow and so on...
Here are some examples of Vray light material used in the scene to substitute all the lights...

[marko04]

Branko, thank you very much. What an eye opener
I have tried quickly to set up the scene like you said, and it is already working. It is working like a dream. My first preview with no real lights, only with light materials, lasted only 45 minutes with exactly the same settings as before. When I put all lights in the scene the way you recommended it will probably be no more than 3 hours per render. Let that numbers tell you about how much you have helped me now. I really appreciate your help.

[d.sign]

For exterior rendering it should be less than 30 minutes for test and about 1,5 hours for final at the size of 1600 pixels, depending on the materials of course...
But main thing is to get a grip of it and than gradually add some lights if they are needed, if not, do not put them in...

You can further optimize the scene by using adaptive DMC and tweaking it... also the Light Cache and all that could be tweaked and finally, all the heavy geometry (trees, cars etc.) should be removed from scene, by turning to Vray proxy and that will further reduce render time and memory consumption...

[marko04]

I forgot to say, in all the excitement... Those are great images. Not only in technical sense, but in choosing all the right angles and making great composition in your images, as well as emphasizing the quality of architecture of those spaces as well. For me, those spaces look alive and vibrant.

[d.sign]

Thanks! Glad you like them...

[simplychen]

may also need to watch out for VRayLightmtl and its intensity. while they can be used as light source, they can and probably will produce more GI splotches if not careful.

another option that you can consider when to check 'enable sub-pixel mapping' under color mapping to reduce aliasing edges which they produce (if it's visible)

[marko04]

Simplychen, I noticed the issues you are talking about... I didnt know that sub pixel mapping is the tool that kills jagged edges of vray mtl.
Thank you very much!

[d.sign]

If you get too much of a splotches in your scene, you can add couple of direct lights to clean it up a bit.
One could be placed as a moonlight source, just a fake of course, you can use Vray sphere light and set it far away and check no decay, adjust intensity to less than 1 and color to gray/purple... increase the diameter of light so it produce fine soft shadows...
That light source will add some extra light outside and clean up the splotches...
As for the splotches inside, I doubt that they will be visible... but if do, put some IES spots in the area that have splotches so direct light cleans it...
As you can see in my examples, splotches are not so obvious even if you do not have any direct light source...
Just increase a bit the Irradiance map parameters...