Mesh cleanup of the Church of the Alamo

August 19, 2009

After completing the work on the Convento/Long Barrack section, I turned to the Church.  I was able to remove about 20 – 25% of the vertices/faces that were not adding significant detail.

My original model was missing a recessed area in the large side walls of the transepts.  This was fixed.  Now I am going to add some detail to the interior buttresses.  I have separated them from the walls because they have a different material.



Sun Lamp Control

August 15, 2009

I created an object for controlling the Sun Lamp.  The Sun Lamp is parented to an Empty which is used to control the Elevation parameter which is in turn parented to another Empty that controls the Azimuth.  By locking the appropriate rotation axes, I now have a convenient way of dialing in the position of the Sun at any time of day.

For the day of March 6, 1836 in San Antonio, I created IPO curves that animate the sun lamp for the entire daylight period.

Sun Angles

August 13, 2009

I should be able to accurately depict the shadows at the Alamo for any given date and time.   Using the NOAA Solar Calculator for San Antonio on the date of March 6, 1836, I found the following data for the position of the Sun (angles in degrees):

Time Azimuth Elevation
06:54 96 0
07:00 97 1
08:00 104 13
09:00 113 26
10:00 124 37
11:00 140 47
12:00 161 53
12:49 182 55
13:00 186 55
14:00 210 51
15:00 228 43
16:00 242 32
17:00 252 20
18:00 260 7
18:37 264 0

Also, using Google Earth, I determined that the long axis of the Convento/Long Barrack is 12 degrees east of true north.

This should be all the information I need to place my Sun Lamp in the model and show accurate shadows.

Cleaning the mesh

August 10, 2009

I have been spending most of my time recently on cleaning the mesh that was ported from trueSpace.  My initial effort is on the Convento section which includes the courtyard walls and the Granary.  First, I found that there were many vertices that were adding complexity but very little detail.  These were removed.  I then removed the faces that would not be seen–the bottoms of the walls, for example.  Finally, I changed areas where many long edges converged to a single vertex (poles) into areas of faces with only four sides (quads).  As a result, I reduced the number of vertices and faces by 40% without any noticeable effect on the detail.

I also separated the section into smaller logical pieces which, along with the cleaner mesh, will help the process of applying more realistic textures to the surfaces.

Before I get to that though, I also have to make a couple of corrections to the geometry.  The Convento needs to be modified to reflect that the ground was lower in 1836 than it is today in the plaza.  Also, the High Wall needs to show the discontinuity in width that takes place near the closed portal.