ECE 104 Fundamentals of Computer Graphics Project 1

Transcription

1 ECE 104 Fundamentals of Computer Graphics Project 1 Due date: April 19 th, 2002 Project Objectives: As part of this warm-up project you will (1) create your first working graphics program based on OpenGL, (2) implement an event-based rendering framework, using GLUT, (3) implement an intuitive graphical user interface based on GLUT or GLUI, (4) learn about window management and initialization and (4) draw and manipulate simple OpenGL primitives. Project Description: Your first project will be the implementation of a 3D viewer that renders models provided in the Fundamentals of Computer Graphics (FCG) file format. You will write a parser for models in the.fcg format, store them in your own data structures and display the described scene using OpenGL. You are expected to implement the following components for this assignment. (a) Create and configure a drawing area (orthographic projection). (b) Write a parser for the.fcg file format. (c) Draw the contents of the provided.fcg files. (d) Allow the user to resize the window interactively (preserve aspect ratio and keep your image in the same relative position). (e) Toggle display modes (solid/wireframe/points) based on keyboard events (S/W/P) (f) Implement keyboard and mouse events that allow the user to translate, rotate and scale the model by manipulating the image area directly with the mouse. For example, pressing the left mouse button and dragging the mouse would translate the object, pressing the right button and dragging the mouse would rotate the scene around the origin of the world coordinate system etc. (g) Create an intuitive user interface for your application based on GLUT/GLUI. (h) Create a model of a table and chair in.fcg format. Project Requirements: The programming language for all projects will be C/C++ and OpenGL for all graphics aspects. We recommend the use of the Microsoft Visual C/C++ environment for developing your application. However, the use of MFC components is not allowed. All source code has to be carefully documented in doxygen compliant form and follow the VIS coding standards. The laboratory machines in EG3151 are equipped with all the necessary tools and you will be required to demonstrate your project in this lab. You may bring your own laptop for the project presentation if you so desire. Project Resources: Information about how to install OpenGL, GLUT and GLUI on your personnel machine can be found under the resources section of the course homepage.

2 Project Submission: All projects have to be submitted electronically before the due-date. A detailed description of the submission process will be available on the course homepage. You will submit a complete version of your project including source files, header files, project files (makefiles), a one page user manual and description of features. Project Presentation: You will be asked to give a presentation of your program and demonstrate its functionality and correctness based on the provided *.fcg examples and your own table/chair model. One additional mystery model will be used during the presentation to test if all features were implemented. HAVE FUN!!!

3 ECE 104 Fundamentals of Computer Graphics Graphics File Format (FCG) The Fundamentals of Computer Graphics (FCG) file format can be used to describe complex geometric primitives in ASCII format. The file format is intended to be extensible and it is up to you to provide additional and more powerful features. Comment lines are identified with a # and should be removed by your parser. The background color of the screen can be specified individually. If more than one instance of this command are encountered the last one will be used. BACKROUND r g b Drawing primitives are defined by PRIMITIVE type num Seven different primitives types are supported. The number identifies how many vertices are used to define it (this information will greatly help you when allocating the required memory). Supported drawing primitives include: POINTS LINES LINE_STRIP LINE_LOOP TRIANGLES TRIANGLE_STRIP POLYGON Individual points Individual lines A series of connected segments A closed line segment (first and last vertex are identical) Individual triangles Linked strip of triangles (the last two vertices are reused) A simple convex polygon More advanced primitives may include (not required for this project) CUBE width Argument is a floating point value for width=depth=height CYLINDER radius Argument is a floating point value for the radius SPHERE radius Argument is a floating point value for the radius CONE radius height Arguments are floating point values for the radius/height Every primitive is described by an ordered set of vertices, which can be associated with additional color and normal information. The following syntax is available: VERTEX x y z COLOR r g b NORMAL x y z The available transformation commands that can be applied to the model are TRANSLATE x y z ROTATE angle x y z SCALE x y z With this information you will be able to describe and construct basic primitives.

4 To support more complex models the language provides a grouping mechanism that enables you to combine shapes and to label them for later use. NEW_GROUP name.... name The group can then be accessed using USE name Groups have their own local scope and use the default world-coordinate system. Operations performed within a group block, such as transformations, do not impact other groups that are defined later. In other words, the NEW_GROUP/ commands behave similar to the glpushmatrix/glpopmatrix operations. Similar to a C/C++ program the file format has a main section that is used to define which geometry will be drawn. This section has to be placed at the end of the file and can call groups that were defined earlier. NEW_GROUP main.... # main is a protected string Extensions for later programming assignments: (not required) Light sources can be added to the scene using the LIGHT token. The following options are supported. LIGHT num num = number of the light in the scene (0-7) INTENSITY r g b Red, green and blue components of the light ( ) LOCATION x y z Position of the light source Other.fcg files can be included using the following command: INCLUDE filename

5 # # This is a simple example of the.fcg file format # BACKGROUND NEW_GROUP face PRIMITIVE POLYGON 4 VERTEX VERTEX VERTEX VERTEX NEW_GROUP front_face COLOR TRANSLATE NEW_GROUP back_face COLOR TRANSLATE NEW_GROUP left_face COLOR TRANSLATE NEW_GROUP right_face COLOR TRANSLATE NEW_GROUP top_face COLOR ROTATE TRANSLATE NEW_GROUP bottom_face COLOR TRANSLATE NEW_GROUP main USE front_face USE back_face USE left_face USE right_face USE top_face USE bottom_face