I hope this reply is helpful to inform your decisions on what I feel is one of the core disciplines in theAutoCAD environment and will help you create better drawings.
There is more going on that just what layer you create and put blocks on in the drawing.
Many things must be taken into consideration.
- Has the company got a robust layer structure?
- Are the blocks likely to be used at multiple levels of detail?
- e.g. a bolt may be required on the fixings layer but also may also be required in a hidden detail!
- Are you using the Tool pallets to enforce later structure and therefore drawing integrity?
- Is the item required to have a different display colour / linetype / thicknessto the origin Layer or layer you have placed it on?
- Do you preferFreeze/Thaw or On/Off to deal with your layout?
Example.
Layer structure for lighting
L1 = Lighting (colour red)
L1 = Lighting-Text (Colour Mono)
A light fitting is created (called 600x600.dwg) with the geometry on layer Lighting and with an attribute that is on layer Lighting-Text (to denote the fitting type).
The fitting is placed in the grid on layer Lighting or layer 0 and freezing either Lighting layer gives the following results.
- Placed on Layer 0
- freeze Lighting-text and only theattribute text is removed from the view
- freeze Lighting and only thegeometry is removed from the view
- Placed on Layer Lighting
- freeze Lighting-text and only theattribute text is removed from the view
- freeze Lighting and both thegeometry and the attribute text are removed from the view
The fitting is placed in the grid on layer Lighting or Layer 0 and Switch Off either Lighting layer gives the following
- Placed on Layer 0
- Switch Off Lighting-text and only theattribute text is removed from the view
- Switch Off Lighting and only thegeometry is removed from the view
- Placed on Layer Lighting
- Switch Off Lighting-text and only theattribute text is removed from the view
- Switch Off Lighting and only thegeometry is removed from the view
BUT
If you; through badplanning or just bad luck you happen to but the light fitting on the Power layer (Colour Blue) you could end up in a bit of a mess. E.g.
- Reflected ceiling plan layout is required
- Freeze the Power layer and the 600x600 disappears!
- Switch Off the Power layer and the 600x600 is still there great! BUT you can’t organise model space viewports with off (it’s a “global” setting) you must use Freeze in VP Freeze = 600x600 disappears! – Oops.
So, let’s look a little differently.
Build the 600x600 fitting with the geometry in layer 0 and the attribute text on layer Lighting-Text
When you place a block that has entities created on layer 0, those entitiesinherit the properties of the layer they are placed on (colour / linetype etc.). Assuming you have not messed around with the colour!
Same scenario
The fitting is placed in the grid on layer Lighting (it is a light fitting after all 😊) and freezing the layers gives the following results.
- Placed on layer Lighting
- freeze Lighting-text and only theattribute text is removed from the view
- which is what I might want if I want to plot it with only the findings for coordination review
- freeze Lighting layer and all the geometry and the attribute text is removed from the view.
- which is what I want as I don't want the References on the drawing without the fitting itself.
The fitting is placed in the grid on layer Lighting and switching off the layers gives the following results.
- Placed on Layer Lighting
- Switch Off Lighting-text and only theattribute is removed from the view
- Switch Off Lighting and only thegeometry is removed from the view.
Also when you place the light fitting on the Power layer it is immediately displayed in blue so obviously incorrect.
A little more control I think you would agree?
N.B.
A little word about off and Freeze.
Off literally removes the geometry from view turning its visibility state to off.
BUT
It is still in the drawing - just not visible!!
Try this if you have a min and have not lost the will to continue 🙂
- start a new drawing and draw something (doesn’t matter what layer)
- switch off the layer
- AutoCAD will warn you that you are switching off the current layer – select “Turn the current layer off”.
- Now that there is “nothing” in the drawing select the move command and d a crossing window to select the things that are now off
- Nothing selected – right
- Now with the move command active type all in the command line
- All the entities are now selected despite them being off
Try the same with the freeze.
You are stopped at the first step because you can’t freeze the current layer.
As it’s effectively not in the drawing at this point it’s in the database but not published in the drawing. (N.B. it’s a little more complicated than that I know but you get the gist).
I could go on about ByLayer and ByBlock setting for blocks but I feel I have added enough..... but if you want me to elaborate please feel free to ask and I will be happy help if I can.
Have fun...
Andy
