Schedule Syllabus Resources

Program4

Create a trackball interface. Your repository will contain template code. Be sure to fill in all the TODO blocks. The interface should allow the object to be rotated and translated in all directions. If the mouse is moving when the button is released, the object should continue to spin. You should use perspective projection. The window should be resizable and when resized the object should maintain the proper aspect ratio.

Fixes to make things work:

• In simple.vert, delete the smooth keyword.
• In RenderEngine.h, in void reshape, add this line at the bottom of the function:
  glViewport(0, 0, newWidth, newHeight);
• Also in RenderEngine.h, in void reshape, the field of view should be set so 60 degrees are visible (the function takes radians).

Here is the code we wrote in class. It goes in the WorldState constructor.

translateToOrigin = glm::translate(glm::mat4(1.0f), -model.getCentroid());
currentModelTransform = translateToOrigin;

Rubric:

Model is at origin	-1: Not at origin	0: At origin
Intuitive interface	0: Interface does not function	1: Click+drag allows rotation, translation along xy, and translation along z.
Perspective projection	0: Incorrect perspective projection	1: Correct perspective projection
Rotation	0: No rotation	1: Incorrect rotation	2: Vertical drag rotations X , horizontal drag rotates Y, non-centered drag rotates Z
XY Translation	0: No translation	1: Vertical drag moves along Y, horizontal drag moves along X
Z Translation	0: No translation	1: Vertical shift+drag moves along Z
Transform order	0: Unnatural transforms	2: Rotation and translation remain natural after manipulation.
Spinning	0: No spinning	1: Spin based on drag velocity
Resize	0: Resize incorrect	1: Object has correct aspect ratio after resize and fills window

Reference solution