Q: The OpenGL canvas flickers when resizing the window or clicking the main menu.

A: Try disabling the repainting of the background by specifying the system property -Dsun.awt.noerasebackground=true.

Q: Does the codebase support HDR images/textures?

A: The codebase we provided does not contain the implementation for loading HDR images (such as rgbe and exr formats). For the textures which should be HDR, like the exponent texture for the blinn-phong shading, you can either create a real HDR texture by implementing HDR i/o and texture creation, or use a LDR texture and scale the fetched value to a larger range.

Q: Should I implement the tangent space computation for arbitrary triangle mesh?

A: You only need to implement computing the tangent space for the given primitives (spheres, etc). And you can implment the general algorithm (there does exist one), too ;-)

Q: For 2.3 (4), do we have to blur the cube map using a shader?

A: Yes. You are supposed to blur the cube map with a shader and then use the blurred one as the static cube map.

Q: But how to gaussian blur a cube map texture with a shader?

A: Study DynamicCubeMap.java. The overall structure of cube map filtering is similar to that of the dynamic cube map.