The Complete DGN to 3MF Conversion Guide

Free-Form Surfaces Support:

DGN: 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:

DGN: 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:

DGN: 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.

Normal Mapping Support:

DGN: Partial support | 3MF: No support

DGN Notes:

Basic normal mapping for visualization

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:

DGN: 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.

Animations Support:

DGN: Partial support | 3MF: No support

DGN Notes:

Simple animation support for design sequences

Impact:

Animations are an important part of many interactive 3D assets, for example in real-time rendering (including games, XR training, assembly instructions, product demos, and other use cases). There are various kinds of animations that can be used on 3D models. In this example model, a rigid animation is used to make the gears spin. Without support for this feature, in this example, the gears won't move.

Rigid Animations Support:

DGN: Partial support | 3MF: No support

DGN Notes:

Basic animation for construction sequencing

Impact:

Rigid Animations are typically used to animate mechanical parts. In this example, the door of this 3D model of a microwave can be interactively opened or closed, using a rigid animation that gradually changes the 3D transformation of the door. Without support for this feature, in this example, the door will just stay in place and won't move.