K-3D is free-as-in-freedom 3D modeling and animation software. It features a plugin-oriented procedural engine for all of its content, making K-3D a very versatile and powerful package. K-3D excels at polygonal modeling, and includes basic tools for NURBS, patches, curves and animation. Workflow Procedural modeling and animation. Interactive tutorials. Unlimited hierarchical undo/redo. Viewing Camera: pan/tilt, zoom, dolly, modeling and tripod modes. Viewing Modes: Detailed selection of visible features. Hide / unhide geometry. Modeling Powerful scene graph Procedural Modeling with complete modeling history. Selection: Objects, meshes, faces, edges, patched, curves, point groups, points. Geometry types: Polygon, NURBS, subdivision, blobby. 3D Primitives: Cone, circle, cushion, cylinder, disk, grid, paraboloid, polyhedron, sphere, torus. Boolean modeling operations (using GTS library). Text: FreeType2 support. Instantiation: Create duplicates without adding gemometry to the scene. Animation Visualization Pipeline allows arbitrary dataflow - any object property can be connected to any other compatible property. Animate any value. Unlimited number of animation channels. Bezier curve channels. Animate modeling operations. Materials and Textures Textures with 16-bit float bitdepth. Procedual RenderMan shaders. Rendering Full RenderMan Support: Aqsis, Pixie, BMRT, PRman, 3Delight, Render Dot C. Extensible support for alternate render engines and models: Yafray. Render OpenGL previews to disk. Scripting Python engine (preferred engine for new script development). K3DScript engine (minimal scripting engine for tutorials / macros). Support for alternate script engine plugins and environments. Compositing Basic 2D compositing. Bitdepth 16-bit float per channel. Supported Formats Geometry Formats: Wavefront OBJ, GTS and a raw format are fully supported, other ones are optional and depend on PLIB installation. Experimental plugins include OpenFX, OFF, RIB and X formats. Image Formats: JPEG (all platforms). PNG (all platforms). TIFF (all platforms). OpenEXR (requires optional OpenEXR plugin). BMP (requires optional ImageMagick plugin). SUN (requires optional ImageMagick plugin).