3D modeling and length, width, height question

[deadseasquirrels]

I am trying to draw 3D models for the first time, and something is confusing me. Sometimes when I draw a rectangle and it asks for a length width and height it seems the width means something else and the width means something else. I think the width means the distance from the z-axis on the XY plane, but then sometimes it is the distance from the Y-axis on teh XZ plane. I am just wondering if there is a good way to keep that a constant, or to remember which the length, width, and height is referring to at any given time.

[robfowler]

The way I normally draw a box is to use the Box tool from the Solids toolbar then enter the starting corner co-ordinates. When prompted to specify corner or (Cube/Length) type in L and press Return. The length now goes along the X axis, the width along the Y axis and the height along the Z axis.

The command line should look like below to draw a box 100 long by 50 wide by 20 high starting the corner at 0,0,0:

Command: _box
Specify corner of box or [CEnter] <0,0,0>:
Specify corner or [Cube/Length]: L
Specify length: 100
Specify width: 50
Specify height: 20

Try this method until you get used to it.

Rob.

[deadseasquirrels]

That is my thinking. But when I do that, the width and the height seems to get mixed up now. I'll try it again to confirm. But I remember when I started doing this, everything was fine, the 3D was as how you described it and that was my understanding of it. But then something happened and everything got screwed up. Is there a possibility that something may have screwed it up?

[robfowler]

Try resetting your UCS to World.

Rob.

[Mercedes]

If you want to draw a 3d rectangle or a 3d box try this:
Select FRONT view in the view pull-down menu
Select LINE in the draw pull-down menu
Pick a point to start the box
Enter the desired dimensions
EXAMPLE
@10<0,@10<90,@10<180,@10<270, then press escape button to exit command
You now have the front profile of the Square or Rectangle
Type PEDIT select the square that you have just drawn
Type Y to make all lines polylines
Use the JOIN command by pressing (J enter) then press enter again to exit the command
Check if the square is joined (one piece)
Type Extrude and select the square
Type in desired length for the depth of the square
Press enter twice to exit the command
Use the 3D ORBIT command to view the 3 dimensional square.
*You may draw any desired shape in front view and PEDIT it together so it is on piece, then you can use the EXTRUDE command to make the object have the desired depth.
**You can also EXTRUDE an object by drawing its front profile then draw a desired path move the object to the endpoint of the path.
Type EXTRUDE select the object you want to extrude
Type P for path then select the path.
Hope this helps

[Mr T]

When I teach solid primitives I avoid the BOX. It is hard to visualise what is happening, whereas a CONE with radius and ht is easy. Also before drawing switch to SE ISometric view so the 3D world is more apparent.

Just draw a rectanlge then EXTRUDE it and forget about box.

Nick

[Kate M]

Mercedes, why not just use the PLINE command to draw your profile (or RECTANG if it's a box), and skip all the PEDIT steps?

[HarryDsouza]

Let me think!
Did you try resetting your UCS to World.

[Randolph]

Hi folks,

1) A rectangle is flat and has no height.
2) A box has a height.
3) Please don't forget about the box command. It's the most important command in 3d modelling, at least for architecture ... ;)
4) Mercedes, that will work, but you can also walk from Vienna to London via Rome.

Concerning the original question:

1) turn the UCS icon on ("View Menu" > UCS Icon > On)
2) when you change views with the "little cubes" in the "views toolbar", the UCS is automatically changed to be xy-parallel to the view. This is confusing. The collegues are right: go to "UCS > World"
3) If you choose "Visual styles" > "realistic" a navigator cube should appear. This is quite helpful to navigate.

4) Go to some iso view.
5) Click the box command
6) draw a rectangle and pull it up.
7) Forget about other methods. EG, extruding a rectangle is only useful, if you want to create a box with an offset of another box.

That's it.

[ReMark]

Did you guys notice that you're responding to a post from 2004? If they haven't figured it out by now (6 years later) they never will. Time for a different career.

[Randolph]

Thanx, ReMark, and no, I did not. That's the 2nd time I didn't watch out before waisting my time ... just because it was on the top ...

[ReMark]

Third time's the charm.

[MikeScott]

lol!

Randolph had some great info though.. It's good to see a new answer with reasoning.

I always polyline my (primarily) rectangular shapes and extrude. I guess I need to get with the times, I've been on too many early versions of AutoCAD.

[Randolph]

Thanx, you're welcome.

[portews]

Did you guys notice that you're responding to a post from 2004? If they haven't figured it out by now (6 years later) they never will. Time for a different career.



I come six years later and ask the same question. Thanks for the help guys!