Z-buffering and perspective We showed how to enable Z-buffering in WebGL, so that nearer objects are visible in the scene, independent of the order in which the objects are rendered. Then we added a simple camera matrix. For now, all our matrix uCamera is provide perspective, so that objects nearer to the viewer appear larger, and objects further from the viewer appear smaller. Building a sphere mesh We created a sphere mesh as follows: Loop over j in an outer loop 0 ≤ j < 16 Within that, loop over i in an inner loop 0 ≤ i < 32 For each value of i and j, add two vertices to build up a triangle strip: (u,v0) = (i/32, j /16) (u,v1) = (i/32, (j+1)/16) sin( The point on the sphere surface at each value of (u,v) is: (x,y,z) = ( cos(φ) cos(θ) , cos(φ) sin(θ) , sin(φ) ) where: θ = 2 π u φ = π v - π / 2 Homework Due next Wednesday before the start of class Start with the included code in hw6.zip. Make a scene that uses squareMesh, tubeMesh and sphereMesh shapes. Do not make a human figure. What I am looking for is something creative and original from you, something that shows that you understand how to create a hierarchical scene using the matrix primitives: mSave, mRestore, mIdentity, mTranslate, mRotateX, mRotateY, mRotateZ, mScale Extra credit: Add a torus to your scene. To create a torus, you can use the same mesh logic that we used to create a sphere, with the following difference: For any given value of (u,v), the point on a surface of a torus with an inner radius of r is given by: (x,y,z) = ( (1 + r cos(φ)) cos(θ) , (1 + r cos(φ)) sin(θ) , r sin(φ) ) where: θ = 2 π u φ = 2 π v