Layer ground level moves when linked

[Lynda]

I have several layers. They are all set to the same ground plane. When all visible in top or side views and layers aligned they all line up perfectly.

I need to use a layer link to view together and render. When I do this, several of the layers are floating in the air by several meters!

This is a garden with house model. There are no storeys and ebery thing has been drawn with a zero +z height.

What is going wrong?

[Lynda]

I've drawn a 3d rectangle on the ground plane on one existing layer. Copied and pasted it in place into a second layer.

With all layers and classes visible and aligned it lines up perfectly.

Change to layer link (all layers)the rectangle is now floating in the air in the second layer!

Is there a layer height over-ride or something that I may have enabled in error!

[Lynda]

Looking at my layer set up box. My layers have varying z and +z heights! I have not set these to anything but 0! The file I am using is a detail taken from a previous file. I have deleted a load of items to make the file smaller.

The original file does not have these changes in z height at all!

The heights vary from z 2095 and z+ 190.5 to z 0 and z+ 0, with variants in between.

Could this have been caused by the several crashes I have been having? (I am presuming the crashes have been caused by the file size - hence I am producing detail in a second file.

VW says that the +z = the thickness of the delta layer. I have taken this to mean the hight above ground level. Am I wrong?

This is incrediblt time consuming!

[Delmer]

Lynda, its not your +/- Z that needs to be consistent, its your layer Z values. When viewed through the layer link the layer Z value is taken into account. The +/- Z does not set the base elevation, but rather the default height of a layer.

For example, on a 3-storey house with basement and 10' floor to floor heights you might have a

basement with +/- Z = 10', Z = -9'

main floor +/- Z = 10', Z = 1'

upper floor +/- Z = 7', Z = 11'

When viewed together the floors of this building will coincide, but when linked they will stack with 10' separation according to their Z differences.

[Lynda]

Yep, that's the problem.

Changed everything back to zero and voila!

[Robert Anderson]

Lynda, the terminology in the manual is imprecise. The Z value of the layer is the relative elevation of its ground plane. The delta-Z is relatively meaningless; all that delta-Z controls is the default height of walls and extrusions. So VectorWorks uses the Z value (NOT the delta-Z) to position layers relative to each other when linking. Just be aware of this when creating layers by hand.

[mike m oz]

Robert - perhaps the way to reduce the confusion is to get rid of the delta-Z protocol and just use just the relative Z heights for stories (or different elements for non architectural scenarios).

Stories would then only be set by their relative Z height with the options of the automatic wall heights being controlled as in the existing Model Setup dialog box ie. as floor to floor or to underside of overhead slab. (to my mind this should be a wall option anyway so that just by selecting the appropriate option you get the required result.

The Model Setup routine could then work as it should to quickly set up and modify the relative heights of stories in a building. Walls would need to automatically respond to changes in floor to floor heights though.

Extrusion to my mind should never be the default layer height (delta-Z). They should always be set by the dialog box which opens when a layer has a delta-Z of zero. If repeat extrusion height is necessary perhaps an option to temporarily set this can be included in the dialog box.