Space Sketches in Architectural Desktop

I’ve been playing with ADT’s Napkin Sketch feature in an attempt to get more of a “freehand” look for space planning. The intent was to remove the “cast in stone” computer look that space plans have when used out of the box. I think concepts need to look a bit loose to give people the impression there is freedom to change them.

The Napkin Sketch Tool can be found in Content Browser (Helper Tools in the Stock Tool Catalog or search for napkin). It is also a command on the Document Menu (load this from Window>Pulldowns>Document Pulldown).

Napkin Sketch works by tracing the AEC objects with multiple lines then combining the traced result into a block. The original objects are not touched but depending on complexity you can get large file sizes. I find it best to use on 2d elevations or simple objects, like spaces, and in a separate view file as detailed below.

There are options for Line Format (sketchiness), Extend lines at corner, and Scale (size or coarseness) to suit the intended plot size. The result is a static block (not display scale dependent) so you have to tailor the settings to the final use.

I’ve found it is fairly successful if you:
~ Create the spaces in constructs as normal
~ Create a view containing the space constructs. I use a division “space” to make this selection easy. The view can be single or multiple levels.
~ Open the View and use the Napkin Sketch Tool selecting the space xrefs as the objects to be sketched.

This creates a sketch block from the spaces and labels. The spaces get a “sketchy look” but the original objects in the view and constructs are untouched. The label text gets incorporated in the block but is not “sketched” so remains readable. You can retain the original space xrefs or remove them (clear from the view properties) leaving just the sketch space block.

The advantage of doing this in a View is it keeps your construct files clean and isolates the large sketch block in the view file so the size only impacts where that view is used. It also allows progressive sketches to be stored as the project develops as sketches are snapshots that don't alter.

If done in a multiple level view the z value of each level is honoured in the sketch so you can orbit and get a 3d perspective space sketch! This can be useful to show spatial relationships in multi-level buildings.

I have made a comparison of the different line formats in the DWF below. You see the original space plan, tight, loose, and messy settings at the same scale. You can also build other elements over the space plan by adding them to the view as the project progresses as seen in the animation at the start of this article.
Download space plan napkin comparison DWF (250kb) Requires free Autodesk DWF Viewer

UPDATE 22-06-2006 - Check out this post for the new concept display capablities in ADT 2007

Visual Styles in AutoCAD/Architectural Desktop 2007 - 2006/03