What is 2.5-dimensional CAD?

[khoshravan]

The source of article:

http://degreedirectory.org/articles/What_is_the_Difference_Between_CAD_and_AutoCAD.html

 

Types of CAD Depending on the type of work you will need to perform, there are different forms of CAD that you may employ. 2-dimensional, 2.5-dimensional and 3-dimensional models each present different types of images in different perspectives.

 

2-dimensional drafts are flat, while 3-dimensional and 2.5-dimensional drawings are useful if you'd like to examine the depth and space of a design.

 

I can understand 2 and 3 dimensional CAD, but have no idea what is 2.5 dimension:?

Also if you know any Autodesk product in this field, let me know.

[SLW210]

See if this helps 2.5D.

[rkent]

The source of article:

http://degreedirectory.org/articles/What_is_the_Difference_Between_CAD_and_AutoCAD.html

 

Types of CAD Depending on the type of work you will need to perform, there are different forms of CAD that you may employ. 2-dimensional, 2.5-dimensional and 3-dimensional models each present different types of images in different perspectives.

 

2-dimensional drafts are flat, while 3-dimensional and 2.5-dimensional drawings are useful if you'd like to examine the depth and space of a design.

 

I can understand 2 and 3 dimensional CAD, but have no idea what is 2.5 dimension:?

Also if you know any Autodesk product in this field, let me know.

 

Older releases of AutoCAD were derisively called 2.5D because their 3D capabilities were very limited. You could view 3D models but creating them was difficult due to the lack of 3D tools.

 

AutoCAD LT might be considered 2.5D as you can view 3D but you can't do much to edit 3D.

[Patrick Hughes]

I've always referred to 2.5 d as a simple wire frame drawing where you are unable to fully hide objects. Things that are drawn using the 3d coordinate system.

[shift1313]

Not sure how i came across this old thread but in the machining world 2.5d is typically a setup where you can make any movements you want in X and Y but you can only go up/down independent of the other axis in Z. So in CAD i would relate that to only being able to Extrude your 2d sketch. While it is 3d you really dont gain very much from it.

[Kadir]

in 2D and 2.5D modelling you describe an object with points and lines. You "pretend" to show 2.5D objects in 3D via some "tricks" like perspective transformation and hidden line elimination.

 

In a true 3D modelling you describe an object with surfaces, i.e., via the light the object reflects. For example you say that there is a sphere at position x,y,z with radius r and color (r,g,b), relative to a light source and your eye (or the camera) by calculating the "normal" vectors coming out from the sphere to your eye, where you "see" a shiny object with some shading and degredation in color. There are no lines or points (unless you explicitely want to draw one).

Edited March 15, 2021 by Kadir
typo

[f700es]

Kadir, this is almost a 10 year old thread

[BIGAL]

A 2.5d written around 1991 for Autocad old post though.

 

Edited March 16, 2021 by BIGAL