The Complete Rhino 3DM to 3MF Conversion Guide.

Free-Form Surfaces Support:

Rhino 3DM: Full support | 3MF: No support

Impact:

Free-form surfaces allow a CAD user to design surfaces with advanced controls over curvature and continuitiy. While these surfaces are common for CAD models (in the form of so-called boundary representations or "B-reps"), they need to be converted to polygonal triangle or quad data to work with most 3D rendering engines - a process called tessellation. In this example, a surface patch is used to describe a part of a curved surface of a product. Without support for this feature, the free-form surface has to be tessellated into quads or triangles.

Quad Meshes Support:

Rhino 3DM: Full support | 3MF: No support

Impact:

Quad meshes are a common way to hand-model and edit 3D models. 3D artists get intuitive control and such meshes are also easy to refine, as well as well-suited for creation of skinned animations. However, real-time rendering pipelines and hardware are usually all based on triangles, so if a 3D model should not be edited any more, it is safe to convert quads to triangles (and engines will do this automatically before sending data to the rendering hardware). In this example, a part of a mesh is modeled with quads. Without support for this feature, quads will have to be triangulated, producing a pure triangle mesh.

Texture Transforms Support:

Rhino 3DM: Full support | 3MF: Partial support

3MF Notes:

Basic texture coordinate transformation

Impact:

Texture transforms describe transformation operations that are applied to 2D texture images or UV coordinates when using 2D texture data on a 3D surface. They can be used, for example, to make sure that material patterns are using real-world scale when rendered on the 3D surface. In this example, such a pattern is used and scaled with the help of a texture transform. Without support for this feature, the texture pattern shows up at the wrong scale.

Multiple UV Channels Support:

Rhino 3DM: Full support | 3MF: Partial support

3MF Notes:

Multiple texture coordinate sets supported

Impact:

Multiple UV channels allow the optimized and sophisticated use of various 3D modeling features at once. For example, one can use one set of UVs and 2D texture data to model a tiling texture or procedural material, and another UV set to leverage a global lightmap or occlusion map of the 3D model. In this example, a combination of tiled texture (UV channel 1) and baked ambient occlusion map (UV channel 2) is used. Without support for this feature, one needs to either give up the tiling property (e.g., by using a tool like RapidPipline to bake a single texture atlas), or give up the ambient occlusion map, as only one UV channel will be usable.

Procedural Textures Support:

Rhino 3DM: Partial support | 3MF: No support

Rhino 3DM Notes:

Basic procedural material support

Impact:

Procedural texture allow the modeling of surface details through mathematical functions, along with artistic control over various parameters. Typically, they are used for patterns like wood grain or other semi-regular structures. Since they are not using any pixels as source data, procedural textures have, in principle, infinite resolution and are very lightweight to describe. In this example, a procedural texture is used to model the look of a wooden material. Without support for this feature, in this case, the wooden parts won't show any visible details.

Normal Mapping Support:

Rhino 3DM: Full support | 3MF: No support

Impact:

Normal maps are used to model shading differences that are arising from small geometric details on a surface, such as fabric structures, visible gaps between bricks forming a wall, or rough rock surfaces. In this example, a normal map is used to model a fabric structure. Without support for this feature, the rendered fabric will look smoother than it actually is in the real world, as the fabric structure won't be visible.

Transparent Materials Support:

Rhino 3DM: Full support | 3MF: Partial support

3MF Notes:

Alpha channel support for transparency

Impact:

Transparency is commonly used for see-through objects, containing (usually partially) transparent surfaces. In this example, a transparent material is used to model the glass window of the microwave, so that one can see inside. Without support for this feature, the inside of the microwave cannot be seen, as the window will be rendered as an opaque surface.

PBR Materials Support:

Rhino 3DM: Full support | 3MF: Partial support

3MF Notes:

Basic PBR material properties

Impact:

PBR materials enable Physically-Based-Rendering (PBR) for a standardized, photorealistic look of rendered images. PBR uses concepts like metallic-roughness or specular-glossiness properties and a microfacet-based modeling of the surface, using a concept called BRDF (Bi-Directional Reflectance Distribution Function). In this example, PBR materials are used to achieve realistic looking plastic and metal materials. Without support for PBR materials, only basic colors and shading can be used (for example, based on more simple shading models, such as the Blinn/Phong model).