Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Chapter 15: Working with the Camera

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 This Chapter: we will learn about One example of implementing Computer Graphics Camera Working with multiple Cameras Examples of interactive camera manipulation Select primitive in 3D scenes

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Changes to Library: 2D to 3D No changes: Primitive: 2D primitives drawn in 3D SceneNode: continue to load M W Matrix Model: continue to be application main class Changes: WindowHandler When loading matrices!

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 WindowHandler: 2D vs 3D

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Lib14: Support for 3D New classes: Camera PrimitiveAxisFrame: Drawing x,y,z axis frame Modifications: WindowHandler Support Camera Load View and Projection Matrices XformInfo Support 3D rotation

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Lib14: New Classes and Changes

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Lib14: The Camera Class

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Lib14: WindowHandler changes

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Lib14: XformInfo Changes Xform Operator in 2D Scale, Translate, Pivot: all 3D quantity Problem: Rotation: θ rotates wrt to z-axis! Xform Operator in 3D (for now) Rotation: (θ x θ y θ z ) Three rotations with respect to each axes

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Lib14: XformInfo details … Xform Operator:

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Tut 15.1: Working with Lib14 Using: Camera and WindowHandler

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Tut 15.1: WindowHandler details

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Lib14: D3D_WindowHandler

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Tut 15.1: DrawHandler

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Tut 15.1: Application CTutorialDlg

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Tut 15.2: Working with 2 Cameras CTutorialDlg class

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Interactive Manipulation of Camera Parameters under explicit user control Camera position Look at position Parameters implicitly controlled Up Vector: try to maintain sense of “up” Parameters typically not controlled Near/Far planes (no real-world correspondence) FOV – zooming control via camera position movement

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Notation and Terminology

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Tut 15.3: Camera Manipulation with the Mouse Left Mouse Button (LMB) Orbit Middle (MMB) Pan Right (RMB) Zoom

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 LMB: Tumble or Orbit the Camera

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Left/Right Orbiting Axis of rotation: The “Up” Direction

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Up/Down Orbiting Axis or rotation: Side Vector

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Orbit: Idea Orbit or Rotate Need Matrix: Camera Position:

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Orbit: Alternatively

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Orbit: Implementation Rotate the World when compute M V Instead of: Compute: Compute and load:

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Lib14: Orbit Support Camera: mouse movement to radians And … using in WindowHandler

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Lib14: Using camera orbit info In WindowHandler:: ComputeViewMatrix

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 MMB: Pan or Track the camera

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Vertical Tracking: (Along UpVector)

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Tracking: Implementation Horizontal/Vertical mouse movements dx and dy Computer Movement vector: Left/Right tracking: along side-vector Up/down tracking: along up-vector Update both camera and at positions:

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Lib14: Tracking Support Camera Class:

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 RMB: Dolly or Zoom the Camera

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Zoom: Implementation Mouse movement: d Move camera eye position in the viewing direction! Watch out!

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Lib14: Mouse Zoom support Camera class

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Drawing the Camera Requires at least two Views! View-A cannot draw the camera of View-A! Can only draw the camera for another view! i.e., View-A draws camera of View-B

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Drawing camera: View Matrix Details Recall: for “orbiting”, we computed and loaded M V with: To properly draw camera-B, from view-A Include camera-B orbiting! Un-do view-A’s camera orbiting ( )

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Implementation: Load into the WORLD matrix

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 3D DC to WC Transformation Must: DC  NDC  EC  WC

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Transform: DC to NDC Assume Recall: Or: In 3D:

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 DC Points and NDC Ray

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 NDC Ray to EC Ray Transform

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 NDC  EC If: In general: or: Given: Then:

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Reconstruct the ray in EC: Given: In general, NDC Point: is a line in EC: Or:

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 EC to WC Transform: Given: Choose convenient z e values z e = 0 and z e = 1 Use to compute WC positions:

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Tut 15.4: Mouse Click to WC Shift-LMB to see the selection ray

Essentials of Interactive Computer Graphics: Concepts and Implementation K. Sung, P. Shirley, S. Baer Chapter 15 Tut 15.4: Device to WC Xform