TAD Docs

In TAD you can intermix freely both 2D and 3D. The reason is that you may be in the initial stages of designing, and you may not have yet decided the value of this property.

The height property decides the height of extrusion that you can set for an object. This extrusion is measured from the level of the object.

Once both the level AND the height is set for a particular object then that object is internally treated as a 3D object. In TAD, there a two ways where both level and height (and a few other properties) can be given.

The value of height can sometimes be negative (when you want to place an object from its top surface. Read also the topic on level for more clarity.

This value can be set at the class instead of specifically for an object. Or it can be set specifically as any object's own property. Usually, you should try to avoid setting it at the object level. The reason is that setting at the class level is far more efficient, time-friendly and TAD file-size friendly.

When you set this property for the class to which an object belongs to, you are effectively setting the same value for the height of ALL the objects in that particular class. You then do NOT have to separately set the value individually for each object. Not just that, it will use the value for future objects that you would create in that class. This is an extremely powerful, time-saving mechanism.

Moreover; when you set this for the class ; you can request TAD to inherit the value into other sub-classes. In the class properties tab you will see an additional column next to the name of the property. If you ALT-Double-Click with your mouse cursor there, TAD will toggle it between inheritable and non-inheritable

When would you want to set this specifically for objects?
The normal reason why someone would specifically set this value for an object is when you want just that object to have a different value than other objects in the same class. This is usually seen in all OOPs (Object Oriented Programming Systems)

Tip
When specifying the numeric value for this property, you can easily give a full mathematical expression here instead of the final value. You can even inter-mix ft and inches too! Internally, all ft and inch are converted to meters. TAD strictly uses the metric system internally for all the eventual values.

For example; if you give 0.3+1'3.25“ It will use the value as 0.68735 That means it intelligently detects 1'3.25” and converts that part into meters.

IMPORTANT Read more about a process called pinning here because you may think that the level from which the object is extruded to the height given for the class/object is from the true ground. Not necessarily! The said class/object could be placed not on the true ground but instead on another surface.