to Problem Solvers..... the Sun and where?

greets,

have autocad 2000,, dont use it a great deal, but can muddle my way around.

i know a church building with a white painted cross on it, and i also know a friend who lives about
a mile away from it;; the terrain level makes my friend a little bit more elevated,, and making
the line of sight easy.

my friends front door would be pretty much looking at the church/cross;; question:::::
1)what sort of data do i need to give autocad in order to find out at what time of day the sun would
hit the cross and bounce over to my friends front door?
2)how do i do it?

hoping for an xmas pressie answer..... be nice ppl.

 

You need to make a 3d model of the entire setup, add materials to the cross,
and then render it using lights and scenes. Sinchy!

 

Once you have your model, if you know anyone who uses 3d max, import it
into there, you can set up a daylight system where you rotate the 3d
model so north is correct, tell max where in the world you are and what
time of day is it and the sun will trace across the sky in the correct
position depending on what time of day you input.

I've never bothered to check if something similar to this is available
in later versions of AutoCAD. But without it, to get accurate readings
you will not only need the house and the church on Nation Grid coords,
but you will then need some way of finding out sun positions relating to
the grid and I wouldn't know where to start with that 1.

 

You don't need 3dMAX. Acad does it all by itself.

 

does it? never needed to use it myself so never bothered to check

 

It does, but it will be a lot of work.

You could download a copy of my program Sunpath from -

http://people.aapt.net.au/jclark19/

Needs longitude and latitude in decimal, hours before or after GMT
(Standard Time or whatever it's called this week).
Program will output sun altitude angle and bearing (azimuth angle) at
hourly intervals for one day each month for 12 months.

Then you could set it up using 2D CAD - or making a cardboard model might
be quicker

 

The lights in acad aren't hard at all, but the modeling can be. However if
all you want to do is calculate the halleluiah moment you just need to model
the front door of the house and the cross, add 'material' to the cross,
create one light, and render until you tweak the light just right.