Finished version w/o filtering yet. Turned out bounce number ftn was overwritten by the new codebase.

Fixed the environment mapping. Apparently EvanEnvironment call had potential issues?

Step 3: triangle texture complete

step 2: sphere texture complete

Step 1:plane texture complete. It turned out I should have passed the texture color object itself, instead of using getValue method.

There is a bug in fetching the texture. Instead, it is constantly using the default value grey set by the parent material class.