#Replicating Light Conds.
6 messages in this thread
We are often called upon to produce an animation of an outdoor scene, a road or
highway, where one question is – what did it look like to the drivers and
witnesses? I am trying to determine the best way to replicate the ambiant light
conditions. I can place the spot at the approximate angle of the sun but that
is not really a great way to do things as there is no exact duplication of
intensity, … I am looking for information that will help with this. So far I
have not found anything that I can use. So… I am asking for help. Does
anyone have a technique for this or is there some reference material source I
could obtain? James L.
The way to do this would be using a photometer and gather values in lux (using
a diffuse filter). Later, you could develop a scale that allows some sort of
conversion into 3D Studio's light values. This is an interesting project. Maybe
John K Jordan could "jump in" and give his ideas (where is the mad scientist
when we need one!).
Gus, That may be a good start. Most of the time we are trying to reproduce the
conditions from several years back. We often have photographs to work from as
well as NOAA information on sunrise, temperature/dewpoint… But I am not
satisfied we are doing things as wellas possible. The problem is, I am not
sure HOW to do things the best way. I am hoping this thread will generate some
interest and some good positive and negative feedback. JL
>>photometers, luxes, filters…
As conditioned as I am to "jumping in" whether I know anything or not <G>, I
have no idea what's going on here. (The previous message must have been a
casualty of my recently developed read, slash, & burn policy for crisis
management.)
JKJ
PS: there are some real mad scientists here – funding has evaporated for some
major nuclear reactor work. They should have learned software, instead. <g>
Hey John, this is the message that started it all:
———————————————————————-
——– We are often called upon to produce an animation of an
outdoor scene, a road or highway, where one question is – what did it
look like to the drivers and witnesses? I am trying to determine the
best way to replicate the ambiant light conditions. I can place the
spot at the approximate angle of the sun but that is not really a
great way to do things as there is no exact duplication of intensity,
… I am looking for information that will help with this. So far I
have not found anything that I can use. So… I am asking for help.
Does anyone have a technique for this or is there some reference
material source I could obtain? James L.
>>reproducing lighting…
Generous Gus, thanks for taking the time to retrieve and repost that.
That does sound interesting.
My first thought is it seems impossibly rich with variables
(atmospheric conditions, diffusion due to cloud cover etc.) One
problem would be how to balance the ratio of ambient to other
lighting (sun, etc.) in 3DS. But how could you go back to the scene
later and duplicate what the conditions were that day? If you could,
then your light meter would make this doable. It seems one could
calibrate the 3DS lighting/gamma values to a set of scanned photos
easily enough. Then if a photo of the scene at the time of the
incident existed, it could be analyzed and 3DS could be adjusted to
match (that view). But the variables!, even the photographic ones.
One could immediately use your most excellent SUNPATH IPAS to place
the sun exactly at the time of day. Besides that, my poor brain is
stuck in low orbit. PS: you'd better get
SENSATIONAL_SOLAR_SYSTEM.PXP ready in case NASA calls and wants to
re-enact that mars probe thing from the driver's and witness'
viewpoints. <g>