> For the complete documentation index, see [llms.txt](https://willadams.gitbook.io/design-into-3d/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://willadams.gitbook.io/design-into-3d/3d-modeling.md). # 3D Modeling 3D Modeling using tools such as Alibre Atom 3D, Blender, and Plasticity Since CAD programs were first created, there have been a number of different approaches. The most common ones, and example implementations may be: * Mechanical modeling --- Alibre Atom 3D, Dune 3D * Mesh sculpting --- Blender * NURBS --- Plasticity 3D This page will consider these three concepts and ways in which they might be used. Dune 3D is an opensource application: {% embed url="" %} and is available as an installable download for Windows: and as source code with instructions for building in Mac OS X and Linux. When first launched, it appears as a small window:
with a list of recent files (if applicable) and buttons for creating a new document or opening an existing one, as well as standard window controls and interface elements for other commands such as maximizing:
Creating a new document brings up a window:
which along with basic commands is discussed at: ## Glossary ### \# 2.5D CAD: 2D Drafting with indication for height/depth 2D Drafting: two-dimensional drawings along X and Y 3D CAD: Drafting or modeling with indication for height/depth/thickness ### A Absolute Coordinates: specifying a position relative to a fixed origin Arc: a curved element relative to, and equidistant from a center point specified by radius and begin and end angles Array: Duplicated objects based on user settings ### C Centroid: The average position of the center of a shape or object Chamfer: Beveled or angled surface along the edge of two adjacent surfaces, c.f., Fillet Chord Length: The straight-line distance between two points on the circumference of a circle. Circle: Figure created by equidistant points from a center forming a closed shape Circumscribed Polygon: A polygon placed within a circle so that all of its vertices are placed on the circumference of the circle Coincident: A constraint or relationship which forces two or more points, lines, or elements to have the same specified position relative to each other Concentric: A constraint or relationship which forces two or more circles or arcs to share a specified center point Constraint: A relationship or rule applied to elements so as to set their relationship or interaction in terms of position Constraint Parameters: Setting which control or define relationship or positioning of elements Construction Drawing: A reference line or other 2D element used for alignment or guiding other elements, usually not included in a final work Control Vertices: Points or nodes or handles used to define a shape Coordinates: Numbers or parameters used to specify position Counterbore: Cylindrical recess to accomdate the head of a fastener Countersink: Conoical recess to accomdate the head of a fastener ### D Datum: A reference element used for a basis of dimensional relationships Deferred Perpendicular: A constraint that forces two lines or objects to be perpendicular to one another after other constraints are applied Deferred Tangency: A constraint that forces two lines or objects to be tangent to one another after other constraints are applied Definition Points: objects placed on a separate, often invisible layer used for construction or reference Degrees of Freedom (DOF): the ability of a point or dimension to be repositioned along one or more axes, c.f., Fully Constrained Diameter: The measurement of a circle from edge-to-edge through the center Dimension: The measurement of an object's size or position relative to a specified origin DXF: Drawing eXchange File: File format used to exchange drawings, may organize objects onto layers ### E Ellipse: a shape defined by a set of points where the sum of the distances between any point on the perimeter and two foci is constant Entity: An object, element, or shape such as a line, circle, or text object ### F Fillet: A curved transition or rounding of an edge where two planes intersect, c.f., Chamfer Fully Constrained: A drawing or model where all elements are constrained or positioned according to defined relationships, c.f., Degrees of Freedom ### G Geometric Constraints: Relationships or rules that maintain specific properties such as parallelism, perpendicularity, or tangency Geometric Dimensioning and Tolerancing (GD\&T): A system of symbols, rules, and practices to communicate and specify dimensions, tolerances, and relationships Grid: An array of horizontal and vertical lines on a specified spacing used as a visual reference and alignment aid ### H Hatches (hatch patterns): Patterns of lines used to fill areas in a drawing to represent materials, surfaces, \&c. Hexagon: A regular polygon with six sides and angles of equal-length and angles (120 degrees) ### I Implied Intersection: An automatically determined point of intersection between two or more lines or curves Included Angle: Angle formed by two lines Infer: Automatic prediction of an action or operation Inscribed Polygon: A polygon placed within a circle so that all of its vertices touch the perimeter Insertion Base Point: Reference point or location where a block or object is pladced Intersection: Point or points at which two or more lines, curves, or objects cross Island: Disconnected or isolated region within a closed shape ### K Key Point: Point which serves as a reference usually for measurement or specifying alignment or relationships ### L Layer: A sub-division of elements into a drawing so that they may be selectively hidden, shown, locked, unlocked, or selected Line: A straight path or segment connecting two points ### M Major Axis: The longer or primary axis of an ellipse (or portion thereof) Minor Axis: The shorter axis of an ellipse (or portion thereof) ### N Nesting: Placing elements which describe parts to be cut out so that they may optimally use material of a specified dimension Non-Uniform Rational Basis Spline (NURBS, B-spline: A curve representation which allows for smooth shapes and flexible control often used for organic elements Nudging: Moving or adjusting objects in increments, often that of grid spacing, or some fraction thereof ### O Ordinate Dimensioning: Dimensions aligned to a common base or reference line Origin: Reference point or coordinate used as a starting point (0,0) Overconstrained: An error state where too many constraints, one or more of which is redundant, have been applied to a drawing, c.f., Fully Constrained ### P Parallel: elements which are equidistant Parametric CAD: A technique where dimensions and positions are specified as values which may be changed/adjusted, causing the model to update Perpendicular: Relationship where two lines or objects meet at a 90-degree (right) angle Perspective: Representation method which creates the illusion of depth and a three-dimensional appearance Point: A specific location or coordinate defined by X,Y, or X,Y, Z position Point of Tangency: Point were a line or curve coincides with a line or curve Polar Coordinate System: Representation of a point using distance and angle from a specified origin Polyline: A connected sequence of line segments Projection Plane: Plane or surface a drawing is projected to or sliced by for a 2D view ### Q Quadrant: Subdivision of a plane into four equal regions based on a central origin Quadratic Curve: Curve mathematically defined by off-curve control point(s) using a formula to arrive at a smooth shape ### R Radius: Distance from the center of a circle or arc Rectangular Array: Arrangement of copies of an original object based on X,Y, positioning Regular Polygon: An object which has all equal sides and angles, i.e., a triangle, square, pentagon, or hexagon ### S Section lines: Lines or hatching in a view of a drawing that indicate the features shown by the cut/slice differentiating interior and exterior Shade: Visual representation of surfaces using tints of grey or colour to depict materials or differently lit surfaces Shoulder: A feature where an edge transitions sharply Spline: Smooth and continuous curve defined by control points allowing for arbitrary shaping of curves ### T Tangent: Relationship or orientation where a line, curve, or surface touches or intersets another line, curve or surface Tolerance: The allowed variation from a dimension ### U Under-constrained: An element lacking sufficient geometric or dimensional constraints to define its position and dimensions ### V Vertex: Point of intersection or connection between lines, curves, or edges ### Z Zero: Reference point or origin of a coordinate system (0,0) or (0,0,0)