CSE581 Au'11 Lab3

CSE581; AU'11; Lab #3: 3D graphics

Due: Monday, Oct. 31, 11:59pm

SUBMISSION - zip up the CL112D-MSVS2010 runnable project and upload it using the Carmen Dropbox

FINAL VERSION - although I might add some more notes or comments as I get feedback from students

Objective

To get you started on OpenGl 3D programming including:

3D viewing, depth buffer
3D primitive objects with normals, use of display lists
interactive camera control
simple lights and material properties
hierarchical modeling and forward kinematics
OpenGL animation: double buffering, timer function

Description

Suggested steps:

STEP1 - Basic viewing
3D viewing: Implement a 3D viewing program to view a groundplane:

Depth buffer

in main, set mode to include DEPTH
in graphics initialization code, enable the Depth_TEST
at the beginning of every display clear the Depth Buffer along with the Color buffer

use glLookAt() to set the camera, look at the origin
set glPerspective() or glFrustum() to something reasonable: make sure your 'near' and 'far' clipping limits can accomodate reasonable camera movement.
Double buffer

in main, set mode to include DOUBLE
and the end of your display routine, glutSwapBuffers() - before the flush)

Display lists: Define objects and use display lists:

you can use OpenGL built-in objects (e.g. glSolidCube(), glSolidTeapot()) but you must define at least one 3D object with normals.
use glGenLists(), glNewList(), glCallList() to define and use objects and normals
define a simple groundplane using a single polygon +/- 100 in x and z at y = 0 or use a cube of the same extent in x and z with top at y=0; use display list to define the cube: GenLists(), NewList(), EndList(), CallList()
Mouse movement: to control the camera

Define &theta, rotation around the y-axis, and \phi, rotation around the z-axis +/- relative to the x-axis, parameters for the camera, and distance from the origin
compute the cameras x,y,z position from the parameters
left mouse button

record x,y screen locations when left mouse button depressed
compute dx,dy when mouse is moved with left button down
convert dx and dy into delta-\theta and delta-\phi, update the angles and recompute the camera position

middle mouse button

record y screen locations when middle mouse button depressed
compute dy when mouse is moved with middle button down
convert dy into zoom-in and zoom-out by modifying distance that the camera/eye is from the origin

use up and down arrows on keyboard to zoom in and zoom out by modifying the distance parameter of the eye/camera

STEP2 - simple lighting
Lighing: Add one or more simple lights to the scene and material properties to objects

during initialization, enable lighting, turn on light 0, setup light 0 using glLightsfv() with ambient and diffuse color.
at each display, set the position of the light right after the LookAt command
instead of using 'Color' to color objects in your scene, use glMaterialfv()
Make sure the normals for the data you use are correct and normalized - either by you or by OpenGL

STEP3 - hierarchical animation & key control
Hierarchical animation: Implment a scene of stacked cubes using relative translations and matrix push/pop commands.

create a stack of scaled cubes to form a column as in the example to the right
Animate the angles at the joints of the stacked cubes.
update state function (called by keystrokes 'c' and 's')

update each angle by some delta value
test the updated angle against angle limits and negate the delta value if exceede
if 'animate', issue glutTimerFunc to call itself

keyboard input: to control the program

'r' - reset camera, animation variables, single step mode
'q' - quit
'c' - continuous run: set 'animate' to TRUE, call update state
's' - single step: set 'animate' to FALSE, call update state (default: start in this mode and reset to it)
'up arrow' - zoom in
'down arrow' - zoom out

STEP4 - complex hierarchy
Complex hierarchy: implement at least one case of a multiple degree of freedom joint and at least one case of two branches in the hierarchy. In my example lab, starting from the bottom, my joints are

one degree of freedom: x-axis rotation
two degrees of freedom: x-axis rotation, z-axis rotation
one degree of freedom: y-axis rotation
the claw:

rotate about z-axis by a, then translate by delta in x
rotate about z-axis by -a, then translate by -delta in x

STEP1 - Basic viewing 3D viewing: Implement a 3D viewing program to view a groundplane: Depth buffer in main, set mode to include DEPTH in graphics initialization code, enable the Depth_TEST at the beginning of every display clear the Depth Buffer along with the Color buffer use glLookAt() to set the camera, look at the origin set glPerspective() or glFrustum() to something reasonable: make sure your 'near' and 'far' clipping limits can accomodate reasonable camera movement. Double buffer in main, set mode to include DOUBLE and the end of your display routine, glutSwapBuffers() - before the flush) Display lists: Define objects and use display lists: you can use OpenGL built-in objects (e.g. glSolidCube(), glSolidTeapot()) but you must define at least one 3D object with normals. use glGenLists(), glNewList(), glCallList() to define and use objects and normals define a simple groundplane using a single polygon +/- 100 in x and z at y = 0 or use a cube of the same extent in x and z with top at y=0; use display list to define the cube: GenLists(), NewList(), EndList(), CallList() Mouse movement: to control the camera Define &theta, rotation around the y-axis, and \phi, rotation around the z-axis +/- relative to the x-axis, parameters for the camera, and distance from the origin compute the cameras x,y,z position from the parameters left mouse button record x,y screen locations when left mouse button depressed compute dx,dy when mouse is moved with left button down convert dx and dy into delta-\theta and delta-\phi, update the angles and recompute the camera position middle mouse button record y screen locations when middle mouse button depressed compute dy when mouse is moved with middle button down convert dy into zoom-in and zoom-out by modifying distance that the camera/eye is from the origin use up and down arrows on keyboard to zoom in and zoom out by modifying the distance parameter of the eye/camera
STEP2 - simple lighting Lighing: Add one or more simple lights to the scene and material properties to objects during initialization, enable lighting, turn on light 0, setup light 0 using glLightsfv() with ambient and diffuse color. at each display, set the position of the light right after the LookAt command instead of using 'Color' to color objects in your scene, use glMaterialfv() Make sure the normals for the data you use are correct and normalized - either by you or by OpenGL
STEP3 - hierarchical animation & key control Hierarchical animation: Implment a scene of stacked cubes using relative translations and matrix push/pop commands. create a stack of scaled cubes to form a column as in the example to the right Animate the angles at the joints of the stacked cubes. update state function (called by keystrokes 'c' and 's') update each angle by some delta value test the updated angle against angle limits and negate the delta value if exceede if 'animate', issue glutTimerFunc to call itself keyboard input: to control the program 'r' - reset camera, animation variables, single step mode 'q' - quit 'c' - continuous run: set 'animate' to TRUE, call update state 's' - single step: set 'animate' to FALSE, call update state (default: start in this mode and reset to it) 'up arrow' - zoom in 'down arrow' - zoom out
STEP4 - complex hierarchy Complex hierarchy: implement at least one case of a multiple degree of freedom joint and at least one case of two branches in the hierarchy. In my example lab, starting from the bottom, my joints are one degree of freedom: x-axis rotation two degrees of freedom: x-axis rotation, z-axis rotation one degree of freedom: y-axis rotation the claw: rotate about z-axis by a, then translate by delta in x rotate about z-axis by -a, then translate by -delta in x