.furproj is a HairWorks project file. This file has scene settings and reference to external files such as fbx models, textures, and .apx HairWorks assets.
.apx and .apb files are HairWorks asset files that are used throughout the art pipeline.
.cps is used to save and load curve and color ramp information per attribute in the curve editor.
.plist is used to cycle through a list of project files for reviews or presentations.
.fbx files are used by the HairWorks Viewer to load model and animation data so the user can iterate on hair with better context.
.dds, .tga, .bmp , .png, .jpg, .gif, .hdr, .pic, and .psd(composited view only) are supported as input textures in the HairWorks Viewer. Textures can be used on models, as a background to the viewport, and as settings textures for HairWorks attributes.