Large evening exterior

[chadc]

I would like to get anyones thoughts on the best way to approach a large exterior evening scene ( Subject is a Stadium and site consitng of 5,000,000 faces, provided by the architect). The scene also consists of 500 +/- exterior and interior lights that have .ies files associated with them. The goal is to give the client a long facade view that they can show the architect and owner what they are getting. I have modified the model to remove the faces that won't be seen.

I have tried scanline + radiosity, but my computer crashes. I would like to use Vray or Mental Ray, but I haven't been able to figure out which settings to change to get fast drafts.

My system is a 3.0 ghz w/ 3GB ram. I have ordered an ATI FireGL V7100 to replace the Radeon X600 to see if that will make any difference in rendering time.

1. What settings for Sun and Sky do you suggest for setting up an evening shot in Vray?

2. Do I have enough computer to get the job done?

3. What Vray or Mental ray settings achieve quick drafts and/or final renders?

I look forward to your insights as I am new to this forum.

Cheers

[kippu]

1. What settings for Sun and Sky do you suggest for setting up an evening shot in Vray?

decrease the sun and sky multipliers and use exponential color mapping , use the sun at an approx place where the sun will be and play with the mapping to decrease or increase the light

2. Do I have enough computer to get the job done?

yes you do!!!! you can also convert them into vray proxies if your viewport is too heavy


3. What Vray or Mental ray settings achieve quick drafts and/or final renders?

vray .. theres a tutorial in the vray forums... to get real fast drafts

[chadc]

kippu,
thanks for your quick response, I will try your suggestions. What would you consider a reasonable amount of time for a draft rendering of this scale?

[kippu]

show me an image ... depends why u using ies.... but drafts usually should not go more than 3-5 mins...

[neha]

chadc, apart from all that kippu has said, some more quick tips to reduce the render times...Lower the secondary bounce and increase the dark multiplier to balance the lighting level. Use low res for renders. While setting up your lights, you can switch off the reflection and filter maps to get quick renders. You can easily set up samples using the low setting preset.Set up low transparency levels and reflection/refraction depths.

[d.sign]

If there is a render engine for such task, it is Vray. However, I am affraid that 500 lights in the scene will make you quite a problem. You can set all shadows to be Vray shadows and lower their samples and in Vray properties meny decrease samles and subdiv for all lights, but still, 500 lights will probably crash any normal computer. If not crash, it will take too long...
All the advices you get are good, but consider that you have such number of lights and they all should be calculated for GI, etc.
Even without GI it would be difficult... Maximum number of lights I used in scene was around 50 for Vray, though it was interior scene and thus had lot more bounces.
My suggestion would be to replace all the light you can with light emitting geometry and use Vray light material... You could try using IES, but 500 lights is insane IMHO. You will not see such amount of lights even in the renders of such powerfull studios like Neoscape. Instead, since you only make exterior shot, use only enviroment light (HDRI would be good). All the interior lights could be simulated either by luminous geometry or by bitmap textures mapped on surfaces that are affected by those lights. Interior could be illuminated by couple of invisible fill lights...
For rendering you can use crop or region option and make shot in more parts to make it easier for computer to work. Since you need long strip image, make it from 3-4 parts and assemble it in Photoshop, I did that with render crop option and it worked good...

[TheAllusionist]

My system is a 3.0 ghz w/ 3GB ram. I have ordered an ATI FireGL V7100 to replace the Radeon X600 to see if that will make any difference in rendering time.

Unless you are using a render engine that uses your graphics processor unit (only one that I know of "RTsquare") to compute rendering, the graphics card has nothing to do with render times. What is does improve is workflow by improving real time performance like navigating the scene, real time animation, etc. Just wanted to toss that in since everyone provided such great advice but didn't touch on this statement.

[chadc]

Thanks to all for the excellent advice, it's good to know there are people out there willing to lend assistance when someone gets stuck.

It seems that the main problem is calculating the bounced light, either GI method or radiosity; therfore, based on your wisodom, I am going to try two approaches. 1. render small portions of the scene and photoshop. 2. break up the model into smaller parts and try a radiosity to bitmap (interior) then Vray. If still no luck, then I will try radiosity to bitmap exterior as well, reasemble and forget about the GI of the environment (sky & sun).

Thanks again. As I am new I am unfamiliar with a few of the acronyms, please explain HDRI, IMHO.

Also I have attached a scanline draft rendering the took a short 4.5 hours. Enjoy. Please keep in mind this draft was only to test the lights for the building, not the environment. Also I turned off the site geometry to save calc. time.

Cheers

[TheAllusionist]

HDRI = High Dynamic Range Images, they contain more information than a typical image, specificaly lighting values and are used for image based lighting. A lot of tutorials on the net.

IMHO = In My Humble Opinion

So you can use a night time HDRI to give your image an appropriate amount of light like from adjacent evening light sources and then bump it up for specific light related to your project as others have suggested. Hope that helps.

[kippu]

wow 4.5 hours in scanline.... you in for a rough ride .... so i am assuming all those hanging lights have ies...you better off deleting them and using a few vraylights there to stimulate light .... just use ies for some uplighters ( even that can be changed into vray light if u prefer).. good luck