Rhino runs on ordinary Windows desktop and laptop computers, with:
- 8 GB or more is recommended.
- Internet connection for installation and validation.
- 600 MB disk space.
- OpenGL 2 capable video card recommended.
- No more than 63 CPU Cores.
- Multiple-button mouse with scroll wheel is recommended.
- Windows 10, 8.1, 8, or 7 – recommended
User interface: extremely fast 3-D graphics, unlimited viewports, shaded, working views, perspective working views, coordinate read-out, named views, floating/dockable command area, pop-up recently-used commands, clickable command options, auto-complete command line, customizable pop-up commands, pop-up layer manager, synchronize views, camera-based view manipulation, perspective match image, configurable middle mouse button, customizable icons and user workspace, customizable pop-up toolbar, transparent toolbars, context sensitive right-click menu, dockable dialogs, multiple monitor support, Alt key copy and OpenGL hardware support with anti-aliasing.
User support and documentation: localized interface (user selectable) and documentation, extensive Explorer-like online help, a 500-page manual, electronic updates, automatic service release availability notification, newsgroup support (24×7), telephone support, and e-mail support.
Construction aids: unlimited undo and redo, undo and redo multiple, exact numeric input, units including feet and inches and fractions, .x, .y, .z point filters, object snaps with identifying tag, grid snaps, ortho, planar, named construction planes, next and previous construction planes, orient construction plane on curve, layers, layer filtering, groups, background bitmaps, object hide/show, show selected objects, select by layer, select front most, color, object type, last object, and previous selection set, swap hidden objects, object lock/unlock, unlock selected objects, control and edit points on/off, and points off for selected objects.
Create curves: point, line, polyline, polyline on mesh, free-form curve, circle, arc, ellipse, rectangle, polygon, helix, spiral, conic, TrueType text, point interpolation, control points (vertices), sketch.>
Create curves from other objects: through points, through polyline, extend, fillet, chamfer, offset, blend, from 2 views, cross section profiles, intersection, contour on NURBS surface or mesh, section on NURBS surface or mesh, border, silhouette, extract isoparm, projection, pullback, sketch, wireframe, detach trim, 2-D drawings with dimensions and text, flatten developable surfaces, extract points.
Edit curves: control points, edit points, handlebars, smooth, fair, change degree, add/remove knots, add kinks, rebuild, refit, match, simplify, change weight, make periodic, adjust end bulge, adjust seam, orient to edge, convert to arcs, a ployline, or line segments.
Create surfaces: from 3 or 4 points, from 3 or 4 curves, from planar curves, from network of curves, rectangle, deformable plane, extrude, ribbon, rule, loft with tangency matching, developable, sweep along a path with edge matching, sweep along two rail curves with edge continuity, revolve, rail revolve, blend, patch, drape, point grid, heightfield, fillet, chamfer, offset, plane through points, TrueType and Unicode (double-byte) text.
Edit surfaces: control points, handlebars, change degree, add/remove knots, match, extend, merge, join, untrim, split surface by isoparms, rebuild, shrink, make periodic, Boolean (union, difference, intersection), unroll developable surfaces, array along curve on surface.
Create solids: box, sphere, cylinder, tube, pipe, cone, truncated cone, ellipsoid, torus, extrude planar curve, extrude surface, cap planar holes, join surfaces, TrueType text.
Edit solids: fillet edges, extract surface, Booleans (union, difference, intersection).
Create meshes: from NURBS surfaces, from closed polyline, mesh face, plane, box, cylinder, cone, and sphere.
Edit meshes: explode, join, weld, unify normals, apply to surface, reduce polygons.
Edit tools: cut, copy, paste, delete, delete duplicates, move, rotate, mirror, scale, stretch, align, array, join, trim, split, explode, extend, fillet, chamfer, offset, twist, bend, taper, shear, orient, orient planar object on curve, flow along curve, smooth, project, object properties.
Annotation: arrows, dots, dimensions (horizontal, vertical, aligned, rotated, radial, diameter, angle), text blocks, leaders, hidden line removal, Unicode (double-byte) support for text, dimensions, and notes. Dimensions in perspective views are supported.
Analysis: point, length, distance, angle, radius, bounding box, normal direction, area, area centroid, area moments, volume, volume centroid, volume moments, , hydrostatics, surface curvature, geometric continuity, deviation, nearest point, curvature graph on curves and surfaces, naked edges, working surface analysis viewport modes (draft angle, zebra stripe, environment map with surface color blend, show edges, show naked edges, Gaussian curvature, mean curvature, and minimum or maximum radius of curvature).
Rendering: shade, shade (OpenGL), shade selected objects, raytrace render (with textures, bumps, highlights, transparency, spotlights with hotspot, angle and direction control, point lights, directional lights, rectangular lights, linear lights, and shadows, and customizable resolution), render preview (OpenGL), render preview selected objects, turntable, RIB export, POV export, rendering plug-in support, settings saved in file.
File formats supported: DWG/DXF(AutoCAD 200x, 14, 13, and 12 ), SAT (ACIS), X_T (Parasolid), 3DS, LWO, STL, OBJ, AI, RIB, POV, UDO, VRML, BMP, TGA, CSV (export properties and hydrostatics), uncompressed TIFF, STEP, VDA, GHS, SLC, Deep Paint 3D.
IGES (Alias, Ashlar Vellum, AutoFORM, AutoShip, Breault, CADCEUS, CAMSoft, CATIA, Cosmos, Delcam, EdgeCAM, FastSurf, FastSHIP, Integrity Ware, IronCAD, LUSAS, Maya, MAX 3.0, MasterCAM, ME30, Mechanical Desktop, Microstation, NuGraf, OptiCAD, Pro/E, SDRC I-DEAS, Softimage, Solid Edge, SolidWorks, SUM3D, SURFCAM, TeKSoft, Unigraphics), NASA GridTool, Yamaha ESPRi, Tebis.
File management: Notes, templates, merge files, export selected objects, save small, incremental save, bitmap file preview, Rhino file preview, export with origin point, work sessions, blocks, file compression for meshes and preview image, send file via e-mail.
How accurate is Rhino?
Since many free-form modelers are not accurate enough for manufacturing or engineering analysis, and since Rhino is a free-form modeler, many people assume Rhino is not accurate enough for their application.
In fact, Rhino is just as or even more precise than most CAD software. Here are the details:
There are two common methods 3-D models are stored in computers.
The first method is using meshes (sometimes called facets), which are usually used for rendering, animation, or conceptual design. While mesh modelers often have what appear to be precise techniques for creating models like spheres, boxes, splines, or even NURBS, behind the scenes they eventually turn everything into a mesh. Meshes are inherently inaccurate because a mesh is simply a collection flat triangles. Even if the surface is curved, a mesh modeler still represents it with flat triangles. This is fine for most renderings, animations, and games, but not when designing for manufacturing. It should be noted that many manufacturing processes use meshes but the mesh density must be under the control of the manufacturing application to achieve the desired accuracy. Rhino does not use meshes for modeling, but it can convert NURBS to meshes at any density as needed for file exports and rendering.
The second method is NURBS. Most CAD, CAM, CAE, and CAID modelers, including Rhino, represent free-form shapes as NURBS. Products that use NURBS can potentially represent free-form shapes accurately enough for the most demanding application if they are diligent in their NURBS implementation. If an application’s primary focus is machinery design and not free-form shapes, it is likely that its NURBS implementation can be less than robust for demanding free-form modeling. This is typical of the mid-range feature-based parametric solid modelers that are so popular today.
Since Rhino’s focus is free-form NURBS modeling, its NURBS implementation is one of the most robust available today. Here are the primary considerations when evaluating whether a modeler is accurate enough for your application:
- Position. Rhino, like most CAD products, represents position in double-precision floating-point numbers. That means the x, y, or z coordinate of any point can have a value ranging from as large as ±10308 to as small as ±10-308. Most CAD software, including Rhino, uses double-precision floating-point arithmetic.Because of the limitation of current computer technology, we expect calculations to be accurate to 15 digits of precision in a range from ±1020 to ±10-20. This limitation is found in all modern CAD products.Older CAD products often have additional limitations because they were developed originally to run on computers with less precision. For example, many CAD modelers are designed for performing calculations on geometry that is restricted to be in a box of size 1000x1000x1000 meters centered at the origin. (Geek alert: Another of the popular off-the-shelf modeling kernels requires parameterizations that are within a factor of 10 of being arc-length parameterizations.) Rhino has none of the limitations found in these older products.
- Intersections. In Rhino, when two free-form surfaces are intersected, the resulting intersection curve is calculated to the accuracy specified by the user. The Rhino default accuracy (tolerance) is 1/100 millimeter. Many CAD systems have built in tolerances that the user cannot override.If you carefully examine the geometry other modelers produce from free-form surface intersections, free-form fillet creation, and free-form surface offsets, you will discover that this free-form geometry is actually calculated with accuracy between 10-2 and 10-4 meters even though they advertise precision of 10-8 (without mentioning that the units are meters).
- Continuity (curvature change matched across a seam.) Most CAD products don’t even have tools to match curvature, let alone do it accurately enough for a discriminating designer. If your application requires smooth free-form surfaces such as airfoils, hydrofoils, lenses, or reflective surfaces, you need these tools found only in Rhino or high-end surface modeling products like CATIA and Alias.
Other things to consider:
- Units. In Rhino the user can specify the units. The units are actually changed and then all calculations are done in those units. In many CAD products, units are only a display attribute. Even though you may have specified millimeters, all of the calculations are actually being done in meters. No big deal. You just move the decimal place over. Wrong! Read on.
- Changing units. Changing units or unit conversions can be one of most commonly overlooked accuracy hazard in CAD/CAM. Most of us might think that converting from imperial units to metric units would introduce some inaccuracy while never giving millimeter to centimeter conversions a thought. Why? Because we think in decimal. But guess what! The computer doesn’t. It is binary (that is base 2, not base 10). That means one or more floating-point multiplies or divides are needed to convert from millimeters to centimeters. The inaccuracies introduced by converting from millimeters to centimeters are the same as those introduced by converting from millimeters to inches.
In summary, Rhino is as accurate or more accurate than any other CAD product on the market today. In addition, Rhino provides tools for setting accuracy and units as well as tools for controlling and evaluating continuity not found in most CAD products. Rhino does not have the limitations found any of the older CAD products.