Welcome to CGarchitect.com Untitled Document

Go Back   CGarchitect.com > 3D SOFTWARE > Mental Ray

Notices

Mental Ray Mental Images Mental Ray (Standalone & application integrated versions)

Reply
 
LinkBack Thread Tools Display Modes
Old April 29th, 2008   #1 (permalink)
Senior Member
 
mskin's Avatar
 
Join Date: Apr 2005
Location: nantucket
Age: 35
Posts: 428

Name: herbert mellville


United_States 


Default photometry

I have created a model in autocad, then file linked it to max.... paying attention to maintaining the correct units. then, after double checking the system units for max, i insert a bunch of photometric lights using web files. i still need to pump them up to 40000 output to get the lights to read. what am i doing wrong/missing and how do i get an accurate lighting model.
mskin is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old April 29th, 2008   #2 (permalink)
Senior Member
 
mattclinch's Avatar
 
Join Date: Jun 2007
Location: W. London
Age: 25
Posts: 315

Name: Matt Clinch


England  Send a message via MSN to mattclinch


Default Re: photometry

what are your exposure control settings?

and what is the value of the 40000? cd? lm?
__________________
Matt Clinch
Arch Viz Artist @ Hayes Davidson
http://www.hayesdavidson.com
mattclinch is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Sponsored Links

Old April 29th, 2008   #3 (permalink)
Senior Member
 
Join Date: Mar 2008
Location: Brooklyn, NY
Age: 35
Posts: 163

Name: Robert Gray


United_States 


Default Re: photometry

Is this a case where you need to do a physically accurate lighting study? Or are you more concerned with capturing the look and feel of the lighting?

There is another thread that discusses this (or at least a similar) topic, albeit with VRay as the renderer in question:

http://www.cgarchitect.com/vb/29800-ies-real-world-lighting-simulations-vray-2.html
RobNJ73 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old April 29th, 2008   #4 (permalink)
Senior Member
 
mskin's Avatar
 
Join Date: Apr 2005
Location: nantucket
Age: 35
Posts: 428

Name: herbert mellville


United_States 


Default Re: photometry

The value is set to cd.

I am not completelyt interested in being physically accurate yet, but it has been mentioned here so it would be nice to be able to do it when asked.

the scene is set to logorithmic with brightness, contraest, MT and Physcal scale set to 65,50,1,1500 and exterior daylight turned on (there will be an exterior light source - mr sky).

I guess that exterior daylight toggle really darkens the scene. im going to try resetting the intensity to the web file and shutting turning that toggle off.

Last edited by mskin; April 29th, 2008 at 10:54 AM.
mskin is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old April 29th, 2008   #5 (permalink)
Senior Member
 
mskin's Avatar
 
Join Date: Apr 2005
Location: nantucket
Age: 35
Posts: 428

Name: herbert mellville


United_States 


Default Re: photometry

Wow, that seams to make the difference. Now what if i want to use a mr sun? ---

the scene is completely washed out. How do i use the mr sun and physically correct photometric lights at once?

Last edited by mskin; April 29th, 2008 at 11:04 AM.
mskin is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old April 29th, 2008   #6 (permalink)
Moderator
 
SandmanNinja's Avatar
 
Join Date: Mar 2007
Location: Ballarat, Victoria, Australia
Posts: 1,375

Name: Joel Callahan


Australia 


Default Re: photometry

you have to change the 1500 default value (dont have it in front of me) to 80,000 to 120,000. I start in the middle - 100,000

That's the value of the brightest light in the scene (i.e. MRSun).

As soon as you do that, the lighting level comes inline with reality.
__________________
-SandmanNinja
website
SandmanNinja is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On


All times are GMT -7. The time now is 11:20 PM.





Powered by vBulletin® Copyright ©2000 - 2008, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.2.0
© Copyright 2001 – 2008 CGarchitect Digital Media Corp. All Rights Reserved.