ACA: Ceiling Grid Boundary Selection and Resource Manager Error

That is a pretty scary warning dialog. It makes me think that, at the very least, my AecGuiBase70 file has some form of corruption. If you receive this error dialog while adding a Ceiling Grid and using the Set boundary command option to select a Polyline as the ceiling boundary, your AecGuiBase70 is just fine. The problem is that the Polyline you selected is not a closed Polyline.

"But wait!" you exclaim. "That Polyline looks closed to me." It may very well looked closed, but when drawing the Polyline, merely snapping the last point to the first point does not a closed Polyline make. Next time, stifle the urge to add one more point on top of the first point, and use the Close command option, by selecting it on the Command Line, or by typing C and then pressing the ENTER key.

Fix the already drawn Polyline by using the Close command option of the PEDIT command or by selecting the Polyline and, on the Properties palette, on the Design tab, under the Misc category, set the Closed property to Yes.

BONUS TIP: You can double-click that Polyline to initiate the PEDIT command on that Polyline. Personally, I would get rid of that last vertex and then close the Polyline, but that is not necessary for the Polyline to be a valid Ceiling Grid boundary.

Curiously, the Set boundary option of the CEILINGGRIDCLIP command provides an informative message at the Command line, rather than the non-informative Error dialog the CEILINGGRIDADD command gives, when selecting an open Polyline as the boundary.

The CEILINGGRIDCLIP command is used to add a clipping boundary to an already-placed Ceiling Grid, and can be accessed by selecting the Ceiling Grid and then, on the Ceiling Grid contextual ribbon tab, on the Clipping panel, by selecting the Set Boundary tool.

Revit: Ceiling Pattern Will Not Move

A hearty thanks goes out to Steve Stafford, who documented the solution to a problem that arose in my office yesterday, way back in 2012, in his Revit OpEd blog.

The problem is that if you use the Move tool with the Disjoin option checked, and then later in that session try to use it to move a Ceiling grid pattern or other model pattern, Revit "remembers" that the Disjoin option was selected previously, and starts out with it turned on. Since Disjoin is not applicable to moving a model pattern, Revit disables (grays out) this option when a model pattern is the object of the Move tool. You might think that since the option is disabled, that it would not have any effect on the command at hand, but you would be wrong. Having this option checked effectively breaks the command, and while you can go through the motions, no change will take place.

To add insult to injury, having the Disjoin option disabled means you cannot clear the checkmark while trying to move a model pattern. The solution, as Steve reported, is to select an object for which the Move Disjoin option is active, such as a Wall, and select the Move tool. Clear the check mark at the Disjoin option on the Options bar, and then press the ESC key twice to exit the command without actually moving the selected object. Now you cah select the Ceiling grid or other model pattern and use the Move tool to reposition the pattern.

Here is a Screencast showing both the problem and the solution, that I put together for users in my office who would rather see the solution than read about it.

ACA Ceiling Grids: Creating a Mask Block

First post in the series: ACA Ceiling Grids: The Cell Component
Previous post in the series: ACA Ceiling Grids: Mask Blocks

As seen in the previous article, Mask Blocks provide a great way to hide unwanted parts of a Ceiling Grid when an item to be placed in the ceiling is larger than one grid cell. The out-of-the-box content contains several light fixtures as part of a Mask Block, but you may need to create your own, to match your office standard graphics.

Mask Blocks have two parts, one required and one optional. The required part is one or more closed 2D polylines, splines, ellipses, or circles, to define the area to be masked. The closed polylines have to be the "newer," optimized LWPolyline type. A single object will define the area to be masked. If more than one object, or "ring" is selected, they must lie completely within or outside of each other; the rings cannot cross or touch each other. The first object will be define a mask area; you will be prompted to indicate whether subsequent rings are "void areas", or holes in the mask area, or an additional mask area.

The second, optional part is additional graphics. If you use the out-of-the-box display settings, the ring(s) selected in for the first part get placed on a non-plot layer; the additional graphics provide the plotable graphics of the Mask Block. The out-of-the-box luminaires that would span two square tiles (2'-0" or 450 mm square) are Mask Blocks with a Multi-View Block for the additional graphics. For the out-of-the-box General and Reflected Display Representations of Mask Blocks, the additional graphics end up on Layer 0, with ByBlock attributes. As these are nested within the Mask Block object, they end up inheriting the properties of the layer on which the Mask Block is placed.

The first step in creating a Mask Block is to draw the closed 2D polyline(s), spline(s), ellipse(s), and/or circle(s) that will define the mask. As previously noted, these items will define a component that is on a non-plotting layer if you are using the out-of-the-box Display Representations.

The mask created will stop short of masking any AEC object linework that is directly under the defining linework, so to mask a 2'-0" square Ceiling Grid for a 4'-0" x 2'-0" object, you can draw the defining closed polyline rectangle with opposite sides of 4'-0" and 2'-0". When aligned with a Ceiling Grid, the crossing grid will be masked, but the perimeter grids will still display.

The next step is to create the additional graphics. For this example, I created a Multi-View Block with the plan graphics for a 4'-0" x 2'-0" supply diffuser. Place an instance of the additional graphics in the proper location, relative to the mask definition object(s).

If you want the additional graphics to pick up the layer, color, linetype, lineweight and plotstyle of the parent Mask Block, then the object(s) for the additional graphics should be on Layer 0, with color, linetype, lineweight and plotstyle set to ByBlock. If your additional graphics include an AutoCAD block or an ACA Multi-View Block, then the objects in the block definition or view block definition should also be on Layer 0 with ByBlock attributes. To set the attributes of an ACA object (such as a Multi-View Block), select the object, right click and choose Edit Object Display from the context menu, and choose the General Properties tab, since these properties are not exposed for ACA objects on the Design tab of the Properties palette.

Finally, open the Style Manager (on the Manage ribbon tab, on the Style & Display panel, choose the Style Manager tool), expand the Multi-Purpose Objects node and select the Mask Block Definitions node. In the right pane, right click on an empty area and choose New from the context menu. Give the new Mask Block Definition a name and, optionally, a description. Right click on the new name and choose Set From... on the context menu.

The Style Manager will close, and the Command Line will display prompts to guide you through the process. The first prompt asks you to "Select a closed polyline, spline, ellipse or circle". Select one of your "rings" that define a masking area; in the example, the 4'-0" x 2'-0" rectangle. The next prompt asks if you want to "Add another ring?". If you only have one defining object, answer "No". If you have additional rings to add, answer "Yes", select another, indicate if it should be a void area and then indicate if you have another ring to select. Once you say "No" to adding another ring, you will be prompted for the "Insertion base point". Choose a point in the drawing to serve as the insertion point for the Mask Block. In the example, I set the lower left corner (grid node) as the insertion point. In response to the "Select additional graphics" prompt, select the additional graphics (if any) to be included in the Mask Block. Press the Enter key when you are done selecting additional graphics, and the Style Manager will reopen. Select OK to dismiss the Style Manager and your Mask Block Definition is ready to be used. Erase your ring(s) and additional graphics if you have no other use for them.

You can now use the MASKADD command to add an instance of the newly created Mask Block Definition and attach it to a Ceiling Grid.

ACA Ceiling Grids: Mask Blocks

First post in the series: ACA Ceiling Grids: The Cell Component
Previous post in the series: ACA Ceiling Grids: Anchors

AutoCAD^® Architecture Ceiling Grids provide an easy way to generate a representation of the ceiling grid for an acoustical panel ceiling. And, as we have seen in previous articles in this series, they have feature that make it easy to locate and organize ceiling devices. There are occasions, such as when using 2x4 luminaires in a 2x2 ceiling grid,

where specific segments of the grid need to be removed. While you can certainly use linework to create a custom grid with just the grid segments you need, it can be tedious to update should design changes move things around. A Mask Block is an AEC object designed just for this situation - using one allows you to "hide" unwanted grid segments without the need for a custom grid, at the same time you are placing the the ceiling object that requires the removal of the grid segment.

In this article, we will make use of an out-of-the-box Mask Block to show how one is used. A future article will show how to create one.

The Design Tool Catalog - Imperial includes a 2x4 fluorescent luminaire Mask Block tool in Electrical > Lighting > Fluorescent, 2x4. For those using Metric units, the Design Tool Catalog - Metric has a 450x900 fluorescent luminaire Mask Block tool in Electrical Services > Fluorescent, 450x900. The images here were taken from the Imperial content. Using the tool to place the Mask Block results in what is seen in the image above. Select the Mask Block and, on the Mask Block Reference contextual ribbon tab, on the Modify panel, choose the Attach Objects tool.

At the Select AEC object to be masked prompt, choose the ceiling grid. In the Select Display Representation dialog, select the Display Representation(s) for which the object is to be masked.

The result can be seen in the image below.

You will only be offered the Display Representation(s) that is(are) turned on for the current Display Configuration and View Direction. If you need the mask to be applied to other Display Representations used by a different Display Configuration (for example, in addition to the Reflected Display Representation shown here, you may need to also apply the mask for the Reflected Screened Display Representation), you will need to change to a Display Configuration/View Direction that makes the other Display Representation active and repeat this process. If you routinely need to mask multiple Display Representations, you may want to create a "working" Display Configuration for reflected ceilings that has all of the various Display Representations for Ceiling Grids turned on, so you can mask all of them at once.

Anchors can also be applied to Mask Blocks, so you can use a node anchor to keep your 2x4 luminaire locked to a node of the grid, as discussed in the previous article. Since the insertion point for this Mask Block is at a grid point, no offset is required.

Note also that, unlike copies of anchored AEC objects, copies of the Mask Block will not inherit the mask. You can, however, select multiple Mask Blocks that occur within a single Ceiling Grid and mask them all at once, so it is probably best to place all of your instances and then apply the mask for all at one time. Once masked, you can move the Mask Block around in the same grid and it will continue to mask any part of the grid that falls behind the mask.

Next post in the series: ACA Ceiling Grids: Creating a Mask Block

ACA Ceiling Grids: Anchors

Previous post in the series: ACA Ceiling Grids: The Cell Component

One useful feature of Ceiling Grids is that you can anchor other AEC objects to the grid (just like any other AEC Grid). Once anchored, if you move the Ceiling Grid, the anchored object(s) will move with it, which makes small adjustments to ceiling grid locations much easier to do. You can find a number of Anchor tools in the out-of-the-box Stock Tool Catalog, in the Parametric Layout & Anchoring Tools category.

Many times objects placed in a gridded ceiling need to be centered in the ceiling panels.

You might think that the Cell Anchor would be the perfect anchor for this arrangement. While it will anchor a Multi-View Block to a Cell component of a Grid (which, if the insertion point of the Multi-View Block is at its centroid, would center it), it will, unfortunately, also rescale the Multi-View Block such that the X- and Y-scale factors of the Multi-View Block match the Cell's X and Y dimensions.

That is not likely to be the desired result.

You could place the object at the desired location and use an Object anchor to tie the Grid, and if the Grid moves, the object would also move, but that would not prevent the object being accidentally moved, since the object can still be moved independently of the Grid.

Using a Node anchor provides the best result.

For objects where the insertion point is not at a node of the Ceiling Grid, you can set X- and Y-offsets to position the object as desired. You can select the object and on the Properties palette, on the Design tab, in the Basic category, in the Location on node subcategory, select the Anchor worksheet. Change the X and Y values for Insertion Offset to move the anchored object relative to the Node to which it is anchored.

Depending upon how the Ceiling Grid was created, you may have to experiment with the sign applied to the offset values to get the object to the desired location. You may find it easier to select the object, right click and choose Node Anchor > Set Offset.

Then select the point to which you want to offset the object, in this case, snapping to the CENter of the Cell component will give the desired result.

The Node Anchor will prevent the object from being accidentally moved a small amount. The object can be moved, but only from one node to another. If you copy the anchored object, the copies will be anchored to a node of that grid, also, making it easy to place additional copies within that ceiling.

Next post in the series: ACA Ceiling Grids: Mask Blocks

ACA Ceiling Grids: The Cell Component

Like all ACA grid objects, a Ceiling Grid has a Cell component, which marks the center of each cell in the grid. You may not be aware of this component, since, in the out-of-box Display settings, this component is turned off. It is also mapped to a non-plotting layer (G-Anno-Nplt for US imperial content), so turning the component on will not affect the final plotted output.

The Cell component displays as a circle at the center of each cell in the grid. You can use the CENter OSNAP to place ceiling objects at the center of a ceiling panel.

Next post in the series: ACA Ceiling Grids: Anchors