Autodesk 00128-051462-9310 - AUTOCAD 2008 COMM UPG FRM 2005 DVD, User Manual

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When you are working with a big model, automatically generating spaces from it can be a time-consuming process.
The software needs to process all valid bounding objects visible in the drawing, and calculate spaces for them. Here are
3 tips how for minimizing the time required:
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For Filter boundary set on the Properties palette, select the Walls Only filter to limit processing to walls, curtain
walls, curtain wall units, and door/window assemblies. This is often sufficient to generate the desired spaces.
■
Before starting the space generation, zoom in on the model to decrease the area visible in the drawing area. The
space generation processes all objects visible in the drawing area, so the more objects are visible, the longer the
processing will take.
■
If you need to generate spaces only for specific boundaries, select the bounding objects manually, and pick the
internal points of new spaces individually.
When I try to generate a 3D freeform space from my model, why do I get an error message:Valid boundary
not found?
The space generation mechanism may not be able to detect a valid space boundary for any of the following reasons:
1.The bounding geometry is not 100% closed
Double-check your model to verify that the objects are really enclosing the space. There may be tiny, barely visible
gaps between the designated bounding objects in the building model.
For example, if an interior wall is auto-projected to a roof slab without ceiling, and the interior wall extends only to
the baseline and not to the outside of the outside wall, the 3D freeform space cannot be generated. In such a case you
could create a ceiling under the roof slab, so that walls are projected to the ceiling instead of the actual roof. Or you
could extend the interior wall all the way to the outside of the exterior wall. You could also place a sweep on the wall
to make the top of the wall flush with the sloping roof slab.
2. Objects intended as bounding geometry are not valid for the 3D freeform space generation
The bounding objects for an associative 3D freeform space must belong to the objects listed under “ Bounding Objects
for Associative 3D Freeform Spaces ” on page 1588. Any other AutoCAD Architecture objects, such as railings or AutoCAD
solids, will not be recognized by the space generation. If your selection set includes one of these objects in a bounding
position, it will be filtered out, and the bounding geometry will be considered not closed. To create a valid bounded
space, substitute a valid bounding object for the invalid one. For example, exchange a mass element for an AutoCAD
solid.
3. Not all bounding objects are visible
A 3D freeform space can only be generated in a view that has all bounding objects visible. Typically, in a Plan view
display configuration the slab is not shown, so you cannot generate a valid 3D freeform space. Either activate the
missing bounding objects in the display configuration, or switch to another display configuration where all necessary
objects are visible (like an isometric 3D view), and generate the space from there.
4. Edges of bounding objects touch, but do not overlap
When bounding objects like walls, slabs, and other bodies just touch each other but do not have any overlap, or when
objects intersect only along an edge (to form a line rather than a surface intersection), they are considered open even
though the corresponding real-world components would be closed. In such cases, no 3D freeform space can be created.
To fix this problem, extend one of the objects just far enough to create an overlap.
When I try to generate a 2D or extruded 3D space from my model, why do I get an error message:Valid
boundary not found?
The space generation mechanism may not be able to detect a valid space boundary for any of the following reasons:
1.The wrong Filter boundary set has been chosen
The objects in a drawing that can be used for bounding a space are dependent on the object filter you have selected
for Filter boundary set on the Properties palette during generating the space. For example, if you have selected the
boundary set option Walls Only, then beams or braces that are necessary for the closed boundary will be filtered out,
and no valid space can be created. In that case, change the filter boundary set so that it includes all of your bounding
objects, and generate the space again. The following filter boundary sets are available and include these objects:
1606 | Chapter 36 Spaces