# 3D modelling softwares questions and answers for interview

For mechanical engineer 3D modelling softwares are very useful create models drawings drafting and simulation. This this type of softwares are useful for understanding and visualisation of assembly before its manufacture. This reduces the cost of prototyping and sampling the job.

In industry people uses softwares like AutoCAD, catia,unigraphics, solid Edge, SolidWorks. There are lots of opening and jobs are available in 3D modelling sector for mechanical design engineers. So that I’m sharing 3d modelling related questions which helpful to crack the interview related to 3D Modelling and Drafting.

**1.What Is Drawing Entities?**

**Answer :**

A drawing is created using a no. of entities. A large no. of options are provided to draw the entities depending upon the requirements.

Common entities are:

Point,

Line,

Arc,

Ellipse

Circle,

Polygon,

Spline,

Rectangle, etc

**2.What Is Geometric Modeling?**

**Answer :**

Geometric modeling involves the use of a CAD system to develop a mathematical description of the geometry of an object.

The mathematical description, called a geometric model is contained in computer memory. These operations include creating new geometric models from basic building blocks available in the system.

**3.What Are The Geometric Modeling Techniques?**

**Answer :**

These are various types of geometric models used in CAD:

Based on the dimensioning

Two dimensional modeling

Three dimensional modeling.

Based on the modeling

Wire frame modeling

Surface modeling

Solid modeling.

**4. What Is 2d Vs 3d?**

**Answer :**

2D models are best utilized for design problems, such as flat objects and layouts of building.

3D models are capable of modeling an object in three dimensional according to user instructions. This is helpful in conceptualizing the object since in true 3D models can be displayed in various views and form different angles.

**5. What Are The Advantages Of Cad?**

**Answer :**

- High productivity and reduced lead time.
- Accuracy in design.
- Better central over the complete project process.
- Modifications in design relatively easy.
- Simulations of the computer generated model can reduce or eliminate prototype testing.
- Effective creation of manufacturing documentation.
- Optimized solution can be received.

**6. What Is Applications Cad Software Package?**

**Answer :**

The CAD system is applied, wherever we need to draw, design, and any facilities related to that.

Automated industries,

Manufacturing companies,

Aerospace designs,

Civil engineering plans,

Electrical circuits, etc.

**7. What Is Cad Software Package?**

**Answer :**

Auto CAD, CATIA, Iron CAD, Pro-E, Turbo CAD, Solid Edge, etc..

**8. What Are The Advantages Of Wireframe Modeling?**

**Answer :**

- Simple to construct,
- Designer needs little training.
- It needs less memory space,
- It takes less manipulation time,
- It is best suitable for manipulation as orthographic, isometric and perspective views.

**9. What is the Difference Between Drawing and Modeling?**

**Answer :**

Modeling three-dimensional solid features often begins with creating a two-dimensional sketch that defines a portion of the shape of your part. Sketching involves the creation of lines, arcs, circles, and dimensions. They are familiar steps to anyone who has created a drawing in a CAD product.

**10. What is exploded view in solid works?**

**Answer :**

Exploded view shows an assembly component spread out.

Go to insert -> exploded view or Go to configuration manager-> Right click configuration -> Click new Exploded View-> select the parts one by one to be exploded -> select the direction or angle in which part need to be moved -> Click apply -> done.

**11. What is the application of Circuit Works in Solidworks?**

**Answer :**

Circuit Works is used to create 3D models of electronics cad data. Generally it is used to convert PCB data into solid works.

**12. What is the difference between geometric and dimensional constraints?**

**Answer :**

Geometric constraint is a connection that forces a limitation between one or more geometric elements. Dimensional constraint is a constraint, which determines the geometric measurement of the object.

**13. Where do we use axis? Difference between axis and construction elements?**

**Answer :**

Axis is used in creating Shaft which is the revolving feature. Axis is visible in part design mode and can be selected, but construction elements are invisible in part design mode and can’t be selected. A construction element is a 2D geometric element that is not used for creating geometry, but is used for positioning other 2D geometric elements. A construction element is represented by dashed lines in a sketch. An axis is the line that is defined as an axis of rotation for a revolving surface. An axis is represented as dotted lines in a sketch.… like this.

**14. What is the difference between symmetry command and mirror command?**

**Answer :**

In symmetry command, the original sketch is deleted and the new one is created about the reference plane but with the help of mirror command we can retain both the new one and the original sketch about the reference plane.

**15. What is the difference between spine and spline?**

**Answer :**

* (1). Spine: *Creates a curve passing thro’a point on a plane & normal to one or more other planes.

*Creates a curve passing thro’ several points having tangential Curvature continuity.*

**(2). Spline:**