AutoCAD Layer 0

[dlperrings]

What is the purpose of the zero layer,
when should it be used and when should it not be used?
There is an opinion in the office that it should never be used.

David Perrings, PE

[jaberwok]

The last time this came up, the general opinion seemed to be "use layer 0 for objects that are to be used as blocks, nothing else".

[dlperrings]

John B,

should all of the layers used in creating the block be on layers other than the 0 layer ?

David Perrings

[Steve_Bennett]

Layer 0 can be a most mysterious layer indeed. From what I understand, if you insert something into your current dwg (say dwg A) from another dwg (say dwg B) & the stuff in dwg B is on layer 0, it will insert the stuff from B into A on whatever layer is set current in dwg A.

I sure hope someone else can make this clearer than the mud I just stirred up.

[dlperrings]

Steve,

Thanks for the reply. I checked my autocad books and did not find any real useful discussion of layer zero. Many moons ago, i did come across something that gave a description of layer 0. THe problem with the layer does seem to come into play with inserts and xrefs.

David Perrings, PE

[quiggle]

I have had the most desireable results using layer 0 for only two functions - inserting a complex block with multiple layers and linetypes that I want to maintain or for the linework in simple blocks and symbols that I want to inherit the properties of the layer I will insert them onto. An xref that is inserted on layer zero may be acceptable, but I find it convenient to insert them on their own layer to allow turning each xref on or off individually with one selection.

[dlperrings]

Dear Quiggle,

Thanks for your reply. I think i have come across this rational before.

David Perrings, PE

[Glenn Pope]

for the linework in simple blocks and symbols that I want to inherit the properties of the layer I will insert them onto.
This is good if you use the same block that might be on multiple layers. Otherwise you would need to create copies of the block for each layer you use.

[Mike.Perry]

Hi

Have a browse of the following threads -

Layer for Title Block and Border (http://forums.augi.com/showthread.php?t=4399)

Border on Layer Zero (http://forums.augi.com/showthread.php?t=13573)

Have a good one, Mike

[adampatten]

In our CAD office, the general rule is to insert xrefs on layer 0.

[kbsheppard]

what about those poor misguided people using defpoints layer for viewports???

[LanceMcHatton]

I was talking to someone from Autodesk a while back. I mentioned something about putting things on defpoints. His response was "What?!?! NEVER put things on defpoints! Defpoints is for AutoCAD's use only. If you put things on defpoints, it may cause errors."

I don't know how true that is but we've stopped doing it. We've made standard layers that don't plot to accomodate the "loss of use" of the defpoints layer.

[adampatten]

I am not sure what use Autodesk would have with having layer 'defpoints' as a standard. Maybe someone from Autodesk can fill us in on what defpoints is meant for. In the meantime.... I use it as my viewports layer.

[purvisp]

Adam,
The defpoints layer is used by your dimensions. From the help files:
"definition points
Points for creating an associative dimension. AutoCAD refers to the points to modify the appearance and value of an associative dimension when the associated object is modified. Also called defpoints and stored on the special layer DEFPOINTS."

So, its not a good idea to use this layer for anything else. I make a layer called "Viewports" for my viewports and just make it non-plotting.

[scwegner]

I am not sure what use Autodesk would have with having layer 'defpoints' as a standard. Maybe someone from Autodesk can fill us in on what defpoints is meant for. In the meantime.... I use it as my viewports layer. Defpoints is where AutoCAD puts the points that define dimensions. From the help files:


The DEFPOINTS layer is created automatically the first time a dimension is created in a drawing. Because this layer contains information about dimensions, it should never be deleted because the dimension data in the drawing may become compromised.

Although the DEFPOINTS layer is not intended to be used as a layer for placing objects, it can sometimes be helpful to place reference or construction geometry or other objects that are intended for viewing only.
Frankly, I was a little surprised by that last line. Given the conflicting stories, I'll play it safe and stay well clear.

[scwegner]

Nuts! You beat me. And almost the same wording in the first two sentences even!

[jaberwok]

I stay clear of all layers that acad creates. I assume that If it creates them, it can modify or delete them.

[Mike.Perry]

I am not sure what use Autodesk would have with having layer 'defpoints' as a standard. Maybe someone from Autodesk can fill us in on what defpoints is meant for. In the meantime.... I use it as my viewports layer.Hi

Have a browse of the following thread (and the links found within) -

Model space lines (http://forums.augi.com/showthread.php?t=4179)

Have a good one, Mike

[adampatten]

Interesting. I will have a talk to my manager about this post and see what he says. AutoCAD does crash sometimes a work. Do you think that this might be a reason for some of those crashes?

[devilfrog]

In our office it is a general rule that nothing goes on the the "0" or "def points" layers. Our blocks go on whatever layer they would go on if they weren't blocks and x-refs have their own individual layers so they may be frozen or thawed with ease.
I've noticed if you audit a drawing that anything on the def points layer is moved to the "0" layer which causes all kinds of problems when you don't want something to print. We created a "No Plot" layer that eliminates this problem.

[david.kingham]

Defpoints used to be used in older versions because there was no option to have a layer not plot, only defpoints did this. There is absolutely no reason to use it now.

[Wanderer]

Defpoints used to be used in older versions because there was no option to have a layer not plot, only defpoints did this. There is absolutely no reason to use it now.
~smart aleck mode = on~ but, that's the way we've always done it. ~smart aleck mode = off~