XirusCAD Technology

XirusCAD Highlights


Local refinement whenever you want and wherever you need it. Add flexibility and local detail to the surface only where it is necessary in order to keep a low surface complexity. Subdivide faces, curves or edges and introduce new control points without disrupting smoothness, geometry or shape properties. XirusCAD provides a seamless integration of subdivision into the XirusCAD modeling toolset to enhance the design experience.

100% NURBS Compatibility

Convert your XirusCAD designs to NURBS at any moment during the modeling process. The lossless geometry conversion guarantees downstream workflow compatibility through the XirusCAD-to-NURBS conversion. Similarly, existing NURBS surfaces can be represented as XirusCAD objects.


CAD users can be grouped into 2 categories: either they belong to the experts who know how to painfully create a smooth y-branch surface or they don’t care because they never need them. With XirusCAD you create a flexible, organic and modifiable y-branch within 30 seconds !
(You won’t believe it until you watch our video tutorial: youtube.com/mirrakoi )


Create smooth surface bridges between faces or quads regardless of the surface shape or topology with only a few mouse-clicks. Forget the headache about connecting cylindrical to rectangular topology: just click ‘n’ join the faces  and speed up your design process!

Smooth Surface Patches

The powerful XirusCAD Patch command enables you to overcome topological limitations of traditional NURBS and surface modeling. It is limitless in the number of input curves or edges that it accepts and will always output the desired missing smooth surface patch. The patch command makes high-end surfacing look easy!

Direct Surface Control

The control points  of XirusCAD objects directly lie on the surface. With XirusCAD, you can easily modify the surface exactly  the way you want. You no longer need to worry about adjusting obscure NURBS weights or control points floating around in space.

Tangent, Curvature and Smoothness Control

XirusCAD offers decoupled and direct smoothness control: Directly manipulate tangents, tangent planes and curvatures! Enjoy the unique organic modeling freedom provided by the XirusCAD kernel. A carefully designed UX experience ensures an unmatched smoothness control.

Watertight Junctions (G0, G1, G2)

Easily create watertight junctions between surface patches with high smoothness. Simply select boundaries or edge segments to be joined and choose between G0, G1 or G2 junctions. Instantly, create high-end blendings  and product designs that exhibit highest quality surface properties.

Grasshopper Compatibility

Thanks to the XirusCAD Brep compatibility you can easily input your XirusCAD designs into a Grasshopper workflow. Create complex topology and spectacular shapes with XirusCAD and use Grasshopper to build structures using XirusCAD designs as building blocks.

Technical Details

XirusCAD® simulates immediate responsiveness to tangents, curvature, derivatives, junctions, boundaries and smoothness and provides direct control to adjust the quality of the surface anywhere on the object. Xirus® allows the user to exactly convert the geometry to NURBS or polygons at any moment during the CAD process.

Mirrakoi®’s 3D geometric kernel offers unsurpassed interaction functionality with 3D digital objects during the shape modeling process. Mirrakoi®’s technology enables a superior modeling experience that results in reduced labour, time, and challenges that are encountered in today’s CAD and CAE processes.

Mirrakoi®’s technology is the outcome of fundamental mathematical research. It is distinguished by four key attributes:

  • unprecedented interaction functionality enabled by augmented CAD
  • superior geometry representation
  • increased efficiency and speed when modeling digital high-quality industrial surfaces
  • guaranteed interoperability with industrial standards (100% NURBS and polygon compatible).
XirusCAD® NURBS Subdivision Polygons
Augmented access to geometry
Decoupled control of tangents, curvature & surface points
Watertight junctions
Watertight junctions with direct smoothness control
G0, G1 or G2 junctions between arbitrary parameter lines
Smooth junctions between different topologies
Watertight junctions between different number of control points
Subdivision and local refinement
Select and manipulate entire or partial parameter line
Select and manipulate faces
Maximally localized surface control (2×2 neighborhood)
Interpolating control points
Organic smooth modeling
Direct control of ‘kinkness’, ‘sharpness’, & smoothness of corners
Exact conic sections, spherers, circles, torus, ellipsoids, arcs
Exact transcendental curves (helix, cycloid, etc)
No weight parameters required
Surface extrusion
Surfaces of revolution, lofting, sweeping
Convert to polygons (quads & triangles)
Exact conversion to NURBS
Arbitrary topology