nbul 2004 
  
PROTOTYPE OF A 3D-MODEL OF THE EARTH GLOBE USING PHOTOMODELER 
SOFTWARE 
Rafael Leivas Cristoväo 
Instituto Militar de Engenharia (IME), Departamento de Engenharia Cartográfica 
Praca General Tibürcio, 80 — Praia Vermelha, 22290-270 Rio de Janeiro / Brasil 
Tel / Fax 0055 21 2546 7069 
déwalter@epq.ime.eb.br 
COMMISSION V — WORKING GROUP 6 — Visualization and Animation 
(Prize for Best Papers by Young Authors for Rafael Leivas Cristoväo) 
KEY WORDS: Close — Range Photogrammetry, PhotoModeler, Earth Globe, Animation, Didactic Project, co-ordinates 
transformation. 
Abstract 
As a part of the project "Initiation to Research”, students and their teachers produced a prototype of a spatial model of the Earth 
Globe. The model used has 30,56 cm of diameter, having, therefore, an approximate scale of 1: 41.745.000. 
The prototype was built from digital pictures taken from the distance of 1 meter, denominated photographic matrix of the globe 
model. 
The equipment used was: 
-Digital Camera SONY DSC P-71 
-PhotoModeler Software version 4.0d 
-3D Studio Max 5 Software 
-Software Windows Movie Maker 
First, it was decided to take 24 pictures, 12 of both hemispheres, having, then, 30° between each of them. The camera was placed 
facing the latitudes 45° N and 45° S, orthogonal to the object surface. Care was taken to avoid the light reflex on the object surface 
because it was too shiny. 
The 3D modelling of the globe was made by the PhotoModeler Software. In order to reference points accurately and quickly, it was 
decided to mark them on the cross of the parallels and meridians. 
The Cartesian co-ordinates X, Y and Z of 12 important points in latitude and longitude were calculated and inserted into the 
modelling process. 
The model was exported on VRML format to the 3DS MAX 5 Software to make an animation in the .avi format. 
These procedures could be used for the real Earth Globe, with satellite images showing the whole globe surface. 
1. INTRODUCTION 
As a part of the project “ Initiation to Research “ second year 
students of the Instituto Militar de Engenharia - IME and 
their tutors produced a prototype of a spatial model of the 
Earth Globe built up from digital images from a school globe. 
This has a diameter of 30,56 em which corresponds to an 
approximate scale of 1:41 745 000. 
The equipment used was: 
- Digital camera SONY DSC - P 71 
- Software PhotoModeler, version 4.0 d 
- Software 3D Studio Max 5 
- Software Windows Movie Maker 
The images were taken by the digital camera and then 
processed by the (above) mentioned software. The purpose 
of this didactic project was to orient the students to 
experiment theory and practise of terrestrial photogrammetry. 
The project has the additional purpose of preparing an 
analogue procedure of modelling the real Earth Planet by use 
of satellite images. 
2. PROJECT PLANNING 
In the initial stage of the project the Digital Camera SONY 
DSC — P 71 with the following characteristics was available: 
- nominal focal distance : 8 mm 
- nominal format : 5,9 mm x 4,5 mm 
At first it was necessary to improvise a support, which 
permitted taking all the images of the rotated globe with the 
same geometrical and photographically quality. 
Also It was necessary to shade the intensity of the light in 
order to avoid white spots on the images of the globe. 
2.1 Camera calibration 
After establishing the sufficient conditions for correct 
illumination the camera had to be calibrated according to the 
instructions of the PhotoModeler user manual. The following 
results were obtained : 
- focal distance : 6,745 mm 
- more details can be found at table |