Project 2: 3D transforms and Cameras

Transcription

1 Project : D transforms and Cameras 50pts See schedule on website for the due date and time. The purpose of this assignment is to gain an understanding of how D transforms and viewing works in OpenGL with matrices and vectors. I. Hierarchical Model (5 pts) Model a robot arm. To do this you must compose transformations. Use any models you like. Some working ones are already included in the models/ folder. Here, I will use Cube objects to build the arm (I recommend starting with cubes since they load faster than models with lots of triangles, which speeds up development). No rotation -> User rotates () -> user rotates () -> user rotates () User scales ()

2 You are to model a robot arm with articulated parts. That is, if you rotate (), then () and () should maintain the same relative position and orientation. () can be translated along x and y. () can be scaled along its local x. Note: by default cubes are rendered where its local origin is the center of the cube. The cube should not rotate around its center point. It should rotate around this one: The supplied unit cube is by default drawn where its center is the origin. The user can control the following through the keyboard: ROTATION (number indicates the part of the arm labeled above): ) Unlimited rotation around the world z axis (Q and W for positive and negative rotation) ) Rotation Limited to -5 and +5 around local z (A and S for positive and negative rotation) ) Rotation Limited to -5 and +5 around local z (Z and X for positive and negative rotation) TRANSLATION SCALE ) Move along the world y axis (positive (E) and negative (D)) and the world x axis (positive (R) and negative (T)) ) You can scale the along its local z axis to create a hammer (press H to toggle between a hammer and the default hand)

3 Extra Credits: When the user presses B have a cube drop to the floor (down the world - y axis) always starting at the position at the end of the arm (see below) II. Camera (0 pts) Create a camera that can do the following (this doesn t have to be a separate class but it is a good idea to do it this way to enable code reuse and modularity): ) Switch between perspective and ortho projection (key P) a. You will need to update the projectionmatrix for this. You can use glm::ortho and glm::perspective to generate the matrix. When you switch, make sure that objects show up in a similar position. ) Camera modes (toggle modes with key M) a. st person camera this is typically the type of camera that that is in first person shooters. In fact it is almost identical to DOOM. You don t show your character s body. It is as if the camera is inside the character s head.

4 b. rd person camera follow mode in this mode you can see your player character (a cube) and the camera is set behind the character over the shoulder. So, the camera is always focused on the back of character s head. It is like the character has a pole sticking out of the back of his/her head and there is a camera affixed to the end. ) Move around the world so you can look at the robot arm from different distances and views. a. Forwards (arrow up) b. Backwards (arrow down) c. Turn left (arrow left) d. Turn right (arrow right) III. Add some more objects to your scene (5 pts) ) Add a character (i.e., a different model from the arm) that you can see in rd person camera mode. ) Have fun. Tell a story if you want. Feel free to use only the objects included in the models/ directory or try and get other models: NOTE: The supplied model loader can load.fbx or.obj Extra Credit: You can also make your own models with DsMax, Maya or some other D modeling program which are free for students from autodesk.com. I ll even give you up to 5 pts ( pt per original model) extra credit if you do this but you models must be more substantial than a sphere, torus, cylinder etc. Also note, that it is a good idea to keep the number of triangles in your mesh relatively low so that it doesn t slow your OpenGL program down to much. Note that the modeling programs are pretty complex so it can take a significant amount of time to learn them. But there are plenty of online tutorials and these skills can help to make your future projects look cooler (although not a requirement). CAUTION: when you download models from online or make your own, there is a reasonable chance it may not work or crash your program. Model loading is always a pain, even with professional

5 programs. Many game engines end up writing their own custom format, an exporter for the modeling programs, and an importer for the game engine. SUBMIT: Readme file: create a readme.txt file that explains what works and what doesn t and list any additional above and beyond work that could be considered for extra credit. Put all your files into the DL submission folder.