What is the difference between dimensional constraints and geometric constraints

Parametric drawing can be defined as a technology that is used for designing with constraints. Constraints are defined as restrictions and associations that are applied to 2D geometry. They provide a way to enforce requirements when looking at different designs or when making changes in the design phase of a project. There are two types of constraints: geometric and dimensional.

Geometric constraints are used to control the relationships of objects in respect to each other. Dimensional constraints are used to control the distance, angle, radius, and length values of objects.

It is important to note that you should first apply geometric constraints to determine the shape of a design and then apply dimensional constraints to determine the size of objects in a design. Parametric constraints have a dedicated ribbon tab that groups the tools and their visibility controls in a logical arrangement.

The Parametric Manager Palette allows tabular editing of names, values, and formulas once dimensional parameters are applied. This palette can be launched from the ribbon see Figure 1. Now that we have an understanding of constraints, we will look at Geometric Constraints followed by Dimensional Constraints, as well as some uses of constraints. The Parameters Manager lists dimensional constraint parameters, reference parameters, and user variables that you can use to create, edit, and organize.

You can easily create, modify, and delete parameters from the Parameters Manager. Within the Parameters Manager, you can:. The Parameters Manager also allows you to define parameter groups in the drawing editor. A parameter group is basically a collection of named parameters. It contains a subset of all parameters defined for the current space, but the group can also be empty. Click the Filter icon to create a group, which displays a filter tree on the left vertical panel of the palette where you can show, hide, or expand the group filters.

Drag and drop the parameters from the grid control into a parameter group. The Invert Filter check box displays all the parameters that do not belong in the group. You can filter the display of variables to do the following:. In the Block Editor, the Parameters Manager displays a consolidated view of all parameters and user-defined properties for the block definition. The Parameters Manager palette includes a grid control with three columns Name, Expression, Value by default.

You can add one or more additional columns Type, Order, Show, or Description using the shortcut menu. The Type column affects the formatting of the parameter in the Parameters Manager and Properties palette. It also affects the value of the parameter when the block is scaled. The Type cell for User parameters displays a drop-down list of the value types. The parameter can be sorted and can be set to Show or Hide in the Properties palette. The value of the parameter resets to 1 when you change the type from String to another type.

Parameters can be renamed; equations and values can be entered or modified. Changes to a parameter name are immediately updated throughout the table and in the Block Editor. The parameters for the block definition are organized in the following categories:. You can only add user parameters to the table.

When you delete any item from the table, the item is automatically deleted from the block definition. Geometric constraints are used to determine the relationships between 2D geometric objects or points on objects relative to each other. When the constrained geometry is edited, the constraints are maintained. Therefore, you have a method of including design requirements in your drawing by using geometric constraints. When you change the value of a normal dimension, the geometry resizes accordingly.

Driven dimensions, conversely, are nonparametric dimensions that show the current value of geometry. You must enter the equal sign to assign a global variable to the dimension. If you do not enter the equal sign, you can create a new global variable, but it will not be assigned to the dimension. What is the main difference between a rough sketch and a profile? A rough sketch is imprecise while a profile is the exact sketch used to create a solid feature.

Parametric modeling is a modeling process with the ability to change the shape of model geometry as soon as the dimension value is modified. Parametric modeling is implemented through the design computer programming code such as a script to define the dimension and the shape of the model. Begin typing your search term above and press enter to search. Press ESC to cancel.

Skip to content Home Sociology What advantages do Autodesk Inventor sketches have over freehand sketches? Ben Davis February 16, What advantages do Autodesk Inventor sketches have over freehand sketches? What type of numeric constraints may be applied to sketches? What advantages do CAD drawings have over paper sketches?

What kind of constraint is not numerical CAD? What is a dimensional constraint? Can a drawing be a model? What is the difference between dimensional constraints and geometric constraints?

Typically, the first constraints that you apply to a drawing are Coincident constraints. Numeric constraints are simply number values.

They can be integers or algebraic equations used to control the dimensions or location of a geometric figure. A numeric constraint can refer to measurements such as distance and size, while limiting the range of those possibilities. Why is it important to use constraints when sketching with your 3D modeling program? Because constraints allow you to move shapes accordingly in order to best represent the object you are sketching. Because some shapes come with automatic constraints.

Parametric drawing is a technology that is used for designing with constraints , which are associations and restrictions applied to 2D geometry. Geometric constraints control the relationships of objects with respect to each other. Dimensional constraints control the distance, length, angle, and radius values of objects. The types of numeric constraints that may be applied to sketches are dimensioning and extrusions.

How is a geometric constraint different from a numeric constraint in the inventor program? A geometric constraint "bonds" two geometric parts together.

A numeric constraint constrains an object to a certain measurement or distance. Parametric Constraints. Parametric constraints ensure that a drawing maintains its original precision by maintaining the relationships between an object and world space, between two objects, or within the object itself.

There are two types of parametric constraints : dimensional and geometric. There is one more way to tell.

In the browser open the sketch folder. Fully constrained sketches will have a "pin" in the upper left corner of the sketch icon. See two sketches here. Dimensional constraints control the size and proportions of a design. They can constrain the following: Distances between objects, or between points on objects.

Angles between objects, or between points on objects. Sizes of arcs and circles. The Auto Dimension dialog box shows the number of dimensions and constraints required to fully constrain the sketch.