Layer mask

[IanH]

I would like to have a layer mask.

The layer mask should only affect the one layer. This is vitally important yet subtle difference to simply masking out via a single layer that would affect *all* underlying layers, not just detail on the single layer. So if I place a mask (a transparent line or polygon say), it blocks out detail from the layer, but not from layers beneath.

Basically, I wish to have the ability to 'knock back' detail on a layer, but only in certain areas and only on the one layer.

[Pat Stanford]

I think design layer viewports will give you this capability, but you will probably want to use two layers, one for the full detail and a second for the DLVP.

[IanH]

I would like to be wrong, but I think that the 'mask' layer would affect all layers beneath not just the single layer.

[Pat Stanford]

I just tried it here and it appears that a cropped design layer viewport does what you want.

I can see everything on layers both above and below in the stacking order that are outside of the crop. I can only see object that are above in the stacking order that are over the crop.

[IanH]

I'm not after a cropped viewport. The mask will mask multiple areas of the underlying layer - so the mask needs to cover the whole underlying layer and not just a crop region.

For instance, I may have a number of paths or terraces each textured with some pattern such as stipple, hatch, hardscape, I don't want the pattern to be across the whole area, just an indicative pattern in some areas of the plan.

So I want to mask some of the patterns out, either fully, or partially with a semi transparent mask. Having the ability to place a hatch for example in a mask that would give the effect of rubbing the underlying part of the layer out with a scalpel would give the perfect graphic effect.

At the moment, this is not possible without the layer being the bottom of the stack which cannot be done for other reasons.

Edited June 8, 2009 by IanH

[brudgers]

why not mask it with an annotation object such as a polyline?

[IanH]

Because it affects other layers.