3D novice

Dear colleagues,

being a novice in Volumetric 3D design using autocad, I have a
question:

In a complex scene, I have difficulties picking objects in 3D (always
picking the wrong one) and I am asking myself: would it be a good idea
to have every single volumetric object on an own layer? (to be able to
switch the unused objects on/off)?

Is this a common practise or are there more elegant workarounds?

Any help welcome,

ciao

Tilo

 

It could be done that way, but it's more common to group *similar* objects
on layers, rather than creating a separate layer for *every* object.
___

 

....and I'd add that maintaining multiple viewports, each looking at the
model from a different angle, can really simplify object selection in 3d.
Look into the VPORTS command.

 

You can hold down CTRL and click to cycle through the objects
close together, one after the other, until the one you want is
highlighted. Press ENTER to turn off cycling.

Juergen

 

In a complex scene, I have difficulties picking objects in 3D (always

Someone else suggested the multiple viewports. I don't use them
myself, but prefer to do it using a combination of techniques. This
includes using the Orbit command to change my view so that I can
select the object I want. I also try to create a reasonable number of
layers so that I can turn off some of the stuff. There is an express
tools that allows you to select an object to turn that layer off... I
use this a lot. I've also created custom button macros which will
freeeze all layers, except the current one. Another to turn everything
back on, and another which will freeze just layers with the word DIM
in them, because I name all the layers having dimensions that way.

However, there are inconsistancies with AutoCAD in working with
hidden views. If you use the version that works when you use ORBIT,
and you try to select or snap to an object, you will also snap and
select hidden invisible objects. The older version of HIDE (from the
command line) will not behave this way. (but you loose the ability to
dynamically zoom and pan). The additional complexity is that when you
use ORBIT's hide, it sets a variable that must be reset before the old
HIDE command will work properly. You would type HIDEMODE and set it
to 2D to do this. I've created macro buttons to do this as well.

Joe Dunfee

 

That was me.

Can you do that transparently, say in a from-point/to-point sitch?

 

I do use it transparently for my own work. However, it would not
surprise me if there were some commands which would not allow this.
Also, I was always a little nervous about the orbit command because it
had about a 5% chance of crashing my AutoCAD 2002. If I hadn't saved
within the prior few minutes, I would not use it transparently, but
rather cancel the command I was in, save, then start the command I was
in over again.

On a separate note, because we recently hired a new guy fresh out of
school, we needed to purchase a new station of AutoCAD 2002. We
wanted to try the $99 LT Extendor program to see if it would really
work reliably. (this program enables AutoCAD LT to have many of the
commands available in the full version of AutoCAD) But, since I didn't
want a new guy to have to deal with bugs, I gave the new guy the full
version I had, and I got the LT version.

In a month of usage, I've never crashed AutoCAD LT (with LT
extendor). Furthermore, the new guy with the full AutoCAD has only
had one or two crashes. So, either his work style avoids the bugs I
ran into, or his operating system is making the difference (I have Win
2000, and he has XP).

Joe Dunfee

 

From what little I've seen ORBIT is a resource hog, especially when shading.
(Wonderful extension of acad's 3d capability tho.)

Who makes the "Extendor"?

 

I love SketchUp's use of the middle mouse button as an immediate,
transparent orbit tool. Since I use the middle button in AutoCAD for the
OSNAP pop-up menu, I modified the acad.mnu file to use Ctrl-middle
button as a shortcut to 3DORBIT. The relevant section is


***AUX3
// Control + button
$P0=SNAP $p0=*
'3dorbit


where the ' before the command makes it transparent.

I, too, have occasional crashes with ADT 2004 and 3DORBIT, especially
with larger models.

-Bill

========

 

Who makes the "Extendor"?

I've been using this $99 add-on with AutoCAD LT 2002, and been VERY
impressed. Later versions of AutoCAD LT broke the method LT Extendor
used for a lot of things, but they are currently working on adding
them via other means (i.e. a LISP interpreter)

http://www.lt-extender.com

Joe Dunfee

 

Thanks, mate.

 

Just found this to "hide" and "undohide" objects, not the whole layer.
It gets unwanted objects out of the way so you can work on objects
behind. And undohide works even after a save. Here it is:

(defun COOF (/ ent) ; makes selected object invisible
(setq ent (entget (car (entsel))))
(if (assoc 60 ent)
(setq ent (subst '(60 . 1) (assoc 60 ent) ent))
(setq ent (append ent '((60 . 1)))))
(entmod ent)
(princ)
)

(defun C:UNPOOF (/ ss n ent) ; makes invisible objects visible
(setq ss (ssget "x" '((60 . 1)))
n (1- (sslength ss)))
(while (>= n 0)
(setq ent (entget (ssname ss n))
ent (subst '(60 . 0) (assoc 60 ent) ent)
n (1- n))
(entmod ent))
(princ)
)



I've tested it some but let me know if there are any linitatations to
it.