Irrlicht Engine

Why is it that all of the Quake 3 maps I download from the net don't render all textures in the engine. Do I need the original Q3 texture pack... If so where can I get it? And Can I just add it as a Zipfile Archive?

Please Help me.

yes you can add it just like a zip file, same as the quake3 map demo. The original pak files can be downloaded with the quake3 demo.