Jump to content
Vaiks

Class and Layer: a beginner's question

Recommended Posts

I just started in VectorWorks 12.5 and I came from a Autocad backgroud. I find difficult to understand the difference between classes and layers.

When to use one instead of the other and what are the differences?

Thank you

Share this post


Link to post

Think of them as "Containers of information".

A Layer contains Objects with Class attributes which control how and when they are viewable within the Layer Container.

A Class contains Objects with similar attributes for show, grey, or invisible... in various Layer scenarios.

Layers keep track of bold concepts whereas the embedded Classes keep track of the small details.

For example you can select all objects of a specific Class or you can make global changes to an objects display attributes

via changes to its Class attributes.

Share this post


Link to post

In 2D work a Layer is a division of cyber-space, like the layers of tracing paper that you might use to sketch over a drawing and to draw something else on top of that.

A Class is a non-spatial relationship between objects, like being in the same family or clan, or belonging to the same club, trade union, or social class.

So you could have a Carpenter on the first floor, and another Carpenter on the third floor, and you could select all the Carpenters, wherever they are. That would be a "Custom Selection" using Class as a criterion.

Or you could do something that affects all the people on the third floor (which in this analogy represents a Layer) -- Carpenters and Smiths and Millers alike -- without affecting anyone on the first floor. But while doing it, you'd be able to see everyone on the first floor, if you have Layer Options set to "Show Others".

The Group is important in VectorWorks. It's not similar to what Autocad calls a Group. A VW Group can be thought of as a sub-division of a Layer, or more precisely a container that's located on a particular Layer. A Group can contain objects of many different Classes, but when you put something into a Group, it's not individually associated with a Layer anymore. It's contained in the Group, and so is on whatever Layer the Group is on. If you Ungroup, the ungrouped objects stay on the Layer that the Group was on, and they each keep their own Class status just as they did when you first put them into the Group.

Another way this spatial vs. non-spatial relationship works is that when you Paste an object, you're always pasting it onto the Active Layer. But it keeps the Class it had when you Cut it or Copied it to the clipboard. "Paste-in-Place" can be useful for moving a lot of objects from one Layer to another, or from one file to another, or for moving objects into or out of a Group.

The old adage says, "You can take the boy out of the country (take him out of his Group or off of his Layer), but you can't take the country (his Class) out of the boy." In VectorWorks, you can take the country out of the boy. You can use the Object Info palette to change an object's Class as well as its Layer.

VW Classes are similar to Autocad "Layers" (which aren't layered). VW Sheet Layers are analogous to Autocad's Layout Tabs. VW Design Layers are somewhat analogous to Autocad Modelspace, except that there can only be one Modelspace in a file and it can't be drawn to scale. A single drawing in VW can be divided between several Design Layers as long as they have the same scale. The same file can contain drawings at other scales, each drawn on one or more layers with a different scale than the layers the first drawing is on.

Layers can be used in connection with the associated fill (hatch, solid color, and others) that any 2D object in VectorWorks can have. Hatches can have an optional solid background fill. You can use Layers to control which of two overlapping opaque-filled 2D objects is visible. For example, windows vs. siding on an elevation drawing of a building. If you make the window opaque and put it on a higher layer, it covers up the siding wherever it's located.

You can also control layering and therefore visibility within a single layer, by controlling the stack order (as in Autocad). Any new object is created at the top of the stack for its layer. That includes a new Group made from existing objects, and a new 2D object made by combining two or more objects with the "Add Surface" command. There are several commands that move the current selection set up or down in the stack order.

Share this post


Link to post

To be a little more specific, when documenting a building, I put a floor level on each Layer, and then divide up all objects into useful groups that I might want to turn on and off for each Layer, such as external walls, internal walls, furniture, windows, electric, etc.

Share this post


Link to post

Vaiks, A VectorWorks class is functionally identical to an AutoCAD layer (sorry about the change in nomenclature!) A VectorWorks layer, as has been described, is a container that can have spatial (vertical) attributes, as a building story, and also can be shared using Workgroup Referencing. Think of a class as "what" something is and a layer as "where" something is.

Share this post


Link to post

It is interesting to note that the "VP Integrated Products" cannot understand or acknowledge any other uses for VW than (McMansion) "architecture". I think there are other ways to "integrate" than spatial (vertical) even in (real) architecture.

(OK, I'm breaking my promise not to write here any more. I'm just visiting to find something I contributed... Found it! Cheerio!)

Share this post


Link to post

I don't use layers with a vertical definition. To me the biggest difference is that Layers can have different scales. Of course, I am in mechanical and schematic design... so I'm not sure I matter :)

Edited by Jhaceun

Share this post


Link to post

You don't. Neither do people who need to differentiate data by discipline. Layers are for spatial (vertical) differentiation. Unfortunately, they are not called "building storeys", as they should be.

Share this post


Link to post

Petri, you old curmudgeon, welcome back!

Jhaceun, your opinion does matter, and your assessment is correct. If you don't need layers to control 2D visibility or represent different plan levels, and if you don't do workgroup referencing, then the only thing left is scale. If you didn't need scale either, a single design layer would suffice.

Share this post


Link to post

Petri glad to see that Finland's representative has regained access to this discussion group.

For my work, road design, layers are essential to separate 3-D features at the same scale, for example: layers for underground utilities such as storm drains, sewers, water & layers for surface items such as pavement, sidewalks, landscaping, buildings, etc.

Share this post


Link to post

So, after a while of getting the terms and definitions understood,, I would draft the objects on #1- layer (drawing name) #2 -dimension on another layer (dimension) then add a variation layer #3(v.2.) with maybe a dimension.v.2 #4 and an additions layer #5 and the furnisinngs (seats and stuff) on a #6 layer , maximun of variations with minimum redrawing. So I or the client could view the plan. without the clutter of other info. and change out parts like we would in the real world.

layers make sense in this way to me.

Edited by drawwhat?

Share this post


Link to post

Bruce, why do you have to use Layers for those things rather than Classes?

Share this post


Link to post

Petri, so keeping the Basenjis in line isn't keeping you busy enough. Glad to see your name back on the board!

As is evident from the variety of replies, Layers and Classes are somewhat flexible and can be used within a variety of organization systems. At root, they are two very similar organizing concepts - technically, they are object attributes attached to each object in your file, and you can assign both a layer and a class to every object. (Actually, you must assign both layer and class to every object - there are defaults that automatically assign them to every object created, and you can reassign these attributes at will). If you visualize all objects with the "layer-1" attribute bounded as in a Venn diagram, you can see how the layer can be called a "container," but I think that particular term should be reserved for things like the "group," which is actually an object (in that it can be cut and pasted, unlike a layer or class).

Layers have special capabilities that make them different from classes (i.e., things like z value and +/- z). The designers of VW have conceptualized them as a way to organize a building into stories, as Petri points out. I commonly use several layers to define one story, as I probably don't want to see furnishings in my final drawing but would during design work. But I could equally well assign a class to furnishings, and turn off that class (like freezing a layer) in my viewport.

One of the particularly useful properties of a layer is that a symbol on a layer different from your walls cannot "enter" the wall. So, if you place a toilet symbol next to a wall in your main walls layer, it will get "sucked" into the wall and create an opening in it - as though it were a window or door. But create a layer for equipment, put it there, and you won't have that problem.

Layers also have the property that you can change an object's layer assignment by cutting it and pasting it into a different layer. You can't do that with a class. (Classes must be reassigned via the OIP, and you can reassign layers by that method also if you want to.) This special property of layers is related to the way in which layers interact with your current screen. The current view can be defined through layer visibility control, but beyond that, the active layer is the one in which every object is placed when pasted (and, by default, every created object is placed).

Share this post


Link to post

drawwhat, you should also think about using the viewport annotation space as a kind of layer. This is a bit confusing to a new user, as the viewport capabilities were added on top of a system that had already evolved. The result is that there are now several ways to accomplish the same thing, but I find that putting dimensions in a viewport is a way of keeping clutter out of the design space.

Others find that the lack of dimension association (which only works if the dimensions are in the same layer as the objects) is reason to avoid this method. But, like I say, there are a multitude of different ways of working with VW, each with its own pros and cons.

The earlier comment about using layers as a way of having objects with different "scales" simultaneously visible on the screen is evidence of the way we used to use layers to compose a sheet of drawings. Nowadays, depending on how up-to-date your version is, most users employ viewports and "Sheet Layers" to compose sheets of drawings, and the scale attribute of a layer is no longer so centrally important.

Share this post


Link to post

Just when I thought I was ok.... the dim. association thing is nice , but not absolutely necessary. ,, then the different scale as used for a 'exploded view' for a detail sounds nice. is that how I get my arrow heads and dimension to look proportionate to th edrawing,, _ my mistake was to increase the scale of the object and get pissed that the dimension with it looked too large,, now I see my error! ha ha - what's teh difference tween 'Sheet Layers' and 'Layers' I see up in the top of the drawing screen? - So I gotta learn about ViewPorts too ? ,, ok.

Thanks

Share this post


Link to post

Danny, why not just use the Dimension class to distinguish dimensions from other objects? VW can do it automatically. You won't have to change the Active Class before you dimension.

All those things you mentioned as layers could just as well be classes.

Share this post


Link to post

head cocked to one side , in curious wonder.....

what would be the advantage? the dim. would still associate? and the layer scale could be used to keep detail views in font size relationship? humm? I will have to give 'Class' vs. Layer a comparrasson run... but as I also Build what I draw, or usually -re-draw what I have already built from the drawings... I will have to get back to this.

thanks.

Share this post


Link to post

Petri, I assume you use Archicad now most of the time?

Funny that. But layers are nothing more that an additonal method of organising your data. It does not have to be vertical, horizontal or even at 45 degrees. Plenty of VW users use just layers or just classes or a bit of both. Plenty use just 2D so there are no 3D spatial issues. There is no right or wrong way.

Robert's answer is perfectly clear and to the point. Classes=AC layers, VW layers=another way to organise.

The use of layers also depends how intergated you need to be with other applications. If you need to work with Autocad then the preferred method (for ultimate compatibility) is a single design layer and multiple classes.

It also depends how much you use or intend to use 3D vs 2D. In which case the biggest issue you will face is that each layer has its own view parameters - one layer can display top view whilst the other an isometric. That is the single biggest issue most Autocad users I have trained face when trying to understand layers and 3D in VW.....hence why many build models in one layer and mutiple classes.

Get hold of the excellent VW training DVDs as these explain in detail how layers and classes work.

Share this post


Link to post

Jan15

I use classes to identify objects, for example in the layer Utility-Water System class "Utility-Water-Main" is the Extrude Along Path object representing the underground water main & class "Utility-Water-Appliance" is used for objects on the surface, such as water metres, water valves, water vaults, etc. All of the class objects are correctly sized symbols.

The layer "Roadway Surface" has class objects such as pavement new & existing, curbs, gutters & sidewalks.

Share this post


Link to post

Thanks for the added info.. George & rsa . now I hav a question about the old 'Layer vs. Class' thing,,, I have a floor plan, in 4 layers 1 real parts, 2 to be built parts, 3 all seating , 4 big cabinets,, ( it's a airplane set,,) So now I find i want to make layer 1, 3, & 4 visible , but not 2,,, or some other way to view and print,, Is it Class the turns off & on? can I turn off & on Layers? or do I have to 'cut' and paste the seperate layers into something else?

thanks

Danny

Share this post


Link to post

Danny,

Look through this thread for some class and layer advise. You may want to have your different kinds of items in the airplane on classes rather than layers. This will give you more control over what is visible and what that information looks like.

But back to your question... you can turn layers on, off or gray.

click on the layer window in the upper right hand corner of the window and click on layers...

you can click in the column for visible by the layer you want to turn on. You can turn on or off any combo of layers. Similar process for classes.

click OK

Check your layer options to view all your layers that are on -

right click in the work window. go to layer options and choose show/snap others.

When you have everything the way you want it you can create a view and/or viewport.

Share this post


Link to post

RSA ,

thank you so much,, - I of course knew all that - yesterday, or was that Friday,, but the brain got too full I guess.. so much to remember all at once..

thanks,, I need a bigger desk for more notes..

d

Share this post


Link to post

Danny,

I'd suggest using a single LAYER with the following CLASSES on that layer:

1. real parts

2. to be built parts

3. all seating

4. big cabinets

George

Edited by G_Hannigan (07/24/07 08:50 AM)

_________________________

Dell XPS, WXP Pro, 4GB RAM ATI 512MB Radeon X1650 Pro VW Arch 12.5.1/RW C4D 10

Share this post


Link to post

Ok, Newbie here, trying to get his Sunday-head around the terminology.

If I read this right, Classes are purely 2D references that can exist on many Layers (Floorboards, WCs, luminaires, etc) and can be switched on or off, greyed out, or whatever to assist the drawing process. Layers are 3D in that they can have z-heights. A Layer can be a whole room floor to ceiling or just the floor deck itself. Am I also right in saying that Layers can pass through each other vertically? For example, can a "stair" layer go 3 floors and pass/pass through the actual floor layers the stairs service?

All I want to do is accurately represent in VW the reconstruction of a 10th century Anglo-Saxon Manorial Enclosure and it's requisite buildings that I've been spending my spare time constructing for the past 7 years. Sometimes, however, the ability to understand eludes me entirely. :-)

Share this post


Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


 

7150 Riverwood Drive, Columbia, Maryland 21046, USA   |   Contact Us:   410-290-5114

 

© 2018 Vectorworks, Inc. All Rights Reserved. Vectorworks, Inc. is part of the Nemetschek Group.

×
×
  • Create New...