Slope Markers Extension V2.0

Overview

This extension creates annotation typically used by architects, builders, landscapers, carpenters and others to indicate the slope of surfaces and the edges of those surfaces. The markers are created as groups within the SketchUp model.

Version 2.0 adds two major new features:

• Color coding of the markers based on minimum and/or maximum allowed slope values

• A SketchUp Overlay (SketchUp 2023 and later only) that continuously monitors the slope of faces and edges as you edit the model and draws colors and text to show the current value of the slope.

The extension adds items to the Tools menu and also provides Toolbars for the markers and the Overlay.

It also fixes various bugs from Version 1.

Slope Markers Extension V2.0

Basic Usage

To draw a Slope Marker, either select the Draw Slope Marker item from the Tools->Slope Marker menu, or click the Draw Slope Marker button in the Slope Marker Toolbar. The cursor will change to a right triangle. Click on an edge or face, and a marker will be drawn in the model context at the click location. A tag will be added for each type of marker added to a scene, visible only on that scene. You can change the tag visiblity and update scenes as needed.

The Slope Marker Tool relies on the SketchUp Inference Engine to identify what you have selected when you click. Only edges and faces are allowable selections, as other entities don't have a meaningful slope. If, due to inference, a unique edge or face can't be determined at the picked point, a MessageBox will inform you to try another location. Watch for an "on face" or "on edge" inference tooltip..

To add edges or faces to the Overlay monitor (including ones in top-level groups or component instances), first select them or the containing group or component instance in the model context using the SketchUp Selection Tool (an Overlay is not a SketchUp Tool, so it does not provide a cursor or means for the user to select anything. You must use the Selection Tool first). Then either select the Tools->Slope Marker->Slope Overlay->Add Selected menu item or click the Add Selected button in the Slope Overlay Toolbar. The selected items will immediately start to be monitored in the current scene.

To remove slope markers, simply erase the relevant group (or immediately undo before drawing anything more).

The Overlay menu and Toolbar provide items to remove selected edges and/or faces or to remove all monitored entities, that is, to purge the monitoring list. If too many items are added for monitoring, the Overlay may start to cause performance lags in SketchUp. If this occurs, remove items from the monitoring list until performance improves.

Slope Markers Extension V2.0

Overview

This extension creates annotation typically used by architects, builders, landscapers, carpenters and others to indicate the slope of surfaces and the edges of those surfaces. The markers are created as groups within the SketchUp model.

Version 2.0 adds two major new features:

• Color coding of the markers based on minimum and/or maximum allowed slope values

• A SketchUp Overlay (SketchUp 2023 and later only) that continuously monitors the slope of faces and edges as you edit the model and draws colors and text to show the current value of the slope.

The extension adds items to the Tools menu and also provides Toolbars for the markers and the Overlay.

It also fixes various bugs from Version 1.0.

Basic Usage

To draw a Slope Marker, either select the Draw Slope Marker item from the Tools->Slope Marker menu, or click the Draw Slope Marker button in the Slope Marker Toolbar. The cursor will change to a right triangle. Click on an edge or face, and a marker will be drawn in the model context at the click location. A tag will be added for each type of marker added to a scene, visible only on that scene. You can change the tag visiblity and update scenes as needed.

The Slope Marker Tool relies on the SketchUp Inference Engine to identify what you have selected when you click. Only edges and faces are allowable selections, as other entities don't have a meaningful slope. If, due to inference, a unique edge or face can't be determined at the picked point, a MessageBox will inform you to try another location. Watch for an "on face" or "on edge" inference tooltip..

To add edges or faces to the Overlay monitor (including ones in top-level groups or component instances), first select them or the containing group or component instance in the model context using the SketchUp Selection Tool (an Overlay is not a SketchUp Tool, so it does not provide a cursor or means for the user to select anything. You must use the Selection Tool first). Then either select the Tools->Slope Marker->Slope Overlay->Add Selected menu item or click the Add Selected button in the Slope Overlay Toolbar. The selected items will immediately start to be monitored in the current scene.

To remove slope markers, simply erase the relevant group (or immediately undo before drawing anything more).

The Overlay menu and Toolbar provide items to remove selected edges and/or faces or to remove all monitored entities, that is, to purge the monitoring list. If too many items are added for monitoring, the Overlay may start to cause performance lags in SketchUp. If this occurs, remove items from the monitoring list until performance improves.

Batch Usage

Both the Slope Markers and the Overlay offer batch modes for adding multiple markers in a single operation. The edges, faces, groups, and component instances to be marked or monitored are first selected in the model context using the SketchUp Selection Tool. Then the appropriate menu or Toolbar item is clicked to add the selected items. There is a configuration option to include only faces, only edges, or both. The batch operation does not find edges or faces nested deeper than one level because there is no way to use inference in this mode to decide what you intended to include.

The Overlay also includes Add All and Remove All operations that affect all edges, faces, groups, and component instances in the model context.

Toolbars

There are two Toolbars associated with the extension, one for Slope Markers, and one for the Overlay.

The Slope Marker Toolbar looks like this:

The buttons, top to bottom, are:

• Draw Slope Marker
• Mark Selected
• Configure

The Overlay Toolbar looks like this:

The buttons, top to bottom, are:

• Add Selected
• Remove Selected
• Add All
• Remove All
• Cycle Label Choice

The actions of these buttons are discussed later in this document. Each toolbar button corresponds to an item in the Tools->Slope Marker menu, with the Overlay items in the Slope Overlay submenu.

Coloring

The Extension splits the range of possible slopes into three parts based on configurable values of minmum and maximum. For both Slope Markers and the Overlay, slopes less than the minimum are colored magenta, slopes between the minimum and maximum are colored green, and slopes greater than the maximum are colored red. The coloring offers a quicker but less precise way to check limits than reading the label values on the markers and Overlay. Since the Overlay tracks changing values in real time, it quickly shows whether moving an edge or rotating a face has brought it into or out of compliance.

For example, there may be a minimum slope required for acceptable drainage. A magenta marker shows where this minimum is not met. There may be a maximum slope for accessibility. A red marker shows where the slope is unacceptably steep.

The coloring of Slope Markers is achieved by painting them with color Materials. So, unless the current style is shaded or shaded with textures, you will see the label values as outlines with the default material color on the outlined faces.

Since Overlays do not use the style, they are not affected by the shading aspect of the style. However, the colors used by the Overlay are translucent so that things such as the selection can be seen through them. This also means that materials on faces and edges may show through and affect the appearance of the Overlay.

Edge Markers

There are three kinds of Edge Slope Markers supported:

• Triangle
• Rise and Run Lines
• Text

All three kinds are drawn in an upright plane including the z axis and the edge.

A Triangle marker has a vertical rise edge (parallel to the z axis), a horizontal run edge, and a hypotenuse parallel to the marked edge. Depending on the text label format, it may have both rise and run text labels or just one label along the run.

A Rise and Run Lines marker is essentially the same as a Triangle marker, but the hypotenuse of the triangle is not drawn.

A Text marker displays a single textual label drawn parallel to the marked edge. As such, it always displays a single text string.

Face Markers

There are five kinds of Face Slope Markers supported:

• Equilateral Triangle
• Long Arrow
• Short Arrow
• Upright Triangle
• Upright Rise and Run Lines

The Equilaterial Triangle, Long Arrow and Short Arrow markers are drawn in a plane parallel to the marked face.

The Equilateral Triangle has one side oriented perpendicular to the maximum slope axis of the face ("across the face") and the center line from that edge to the opposite vertex oriented along the maximum slope axis ("along the face"). It has a text label inside the triangle near the across edge of the triangle.

The Long Arrow and Short Arrow markers are similar, varying in the length of the "shaft" of the arrow and the placement of the label text relative to the shaft.

The Upright Triangle and Upright Rise and Run Lines are identical to the similarly-named Edge markers, but they use the maximum slope axis of the face instead of an edge. They are drawn in a vertical plane including the z axis and the maximum slope axis.

Slope Overlay

Because it draws nothing until edges and/or faces are added for monitoring, the Overlay is automatically enabled on every model you open or create. Like all Overlays, it appears in the Overlays window with a checkbox that instantly turns it on or off. After items are added for monitoring, the Overlay will instantly redraw even as you edit the model.

The output of the Overlay looks like this:

In the image, you can see that some edges and/or faces are being monitored (overlayed) and others are not. It is important to choose what to monitor intelligently so as to avoid screen clutter. You can also use the Cycle Label Choice menu or button to quickly change what Overlay information is displayed. It will often be necessary to zoom in and orbit to see the overlay information despite clutter.

If you are working with quads, you will see that even if the midline dividing a quad into two triangles is smoothed, hence hidden, it will display in the Overlay regardless of the setting of View->Hidden Geometry. This behavior is necessary because it is typical that the two triangles comprising a quad do not have the same slopes.

The Slope Marker Overlay can draw two types of information: a colored indicator over a face or edge and a screen text giving the slope value of a face or edge. This information is redrawn during every update of the view. The indicators and text will move, rotate, and zoom with the associated edge or face as you move the Sketchup camera around the view. They will be updated immediately if you edit a monitored edge or face. So, you can watch the color or label of an edge as you move a vertex or rotate a face to see when it falls within the configured limits.

It is important to understand that an Overlay does not add entities to the model, it draws information directly to the view screen in real time. One consequence is that the Overlay information will not be included when you save a model. It will likewise be lost if you export the model to LayOut, to a renderer, or to a 2D or 3D file. To present the information outside SketchUp you will need to take a screenshot.

Unfortunately, the API for drawing text to the screen in an Overlay does not include a feature that is supported in label text drawn using SketchUp's built-in Tool: the labels drawn by the Overlay are visible even when the face or edge they analyze is obscured by things closer to the camera in front of them. The only known fix would involve casting rays through the model to determine obscuration, which could seriously impact performance because it would happen for every monitored object on every refresh of the view! So, judicious removal of obscured faces or edges from the monitoring set is the only currently available workaround.

Configuration

A suite of parameters control what both the Slope Markers and Overlays do. A default set of values is loaded as SketchUp opens. The Configure item in the menu or toolbar opens a dialog that alows you to modify these values for the current session, to save them as the defaults for the next time you launch SketchUp, or to reset them to the extension's own defaults. The configuration dialog looks like this:

Note: If you had a prior version of Slope Markers installed and saved a user default configuration for it, the first time you open the Configuration dialog in version 2.0, you will see a message box informing you that an obsolete configuration was found and is being reset to the defaults. This is needed because the content of the saved configuration was changed for version 2.0.

The fields in the dialog have the folowing effects:

• Run denominator [number]: This is the unit of run for which a corresponding rise will be calculated. The default for imperial units is 12. For metric units it is 100. So, for example, a 45 degree slope would have a rise of 12 and a run of 12 (or 100 and 100). These are unitless because the ratio of rise to run is what defines slope. The ratio does not depend on the units of the rise or run (though they must always be the same * e.g. you can't mark a rise in inches against a run in cm.).

• Marker Length [length]: This is the length at which the marker is drawn in the model. This parameter allows you to size the markers for readability at the current zoom in the view. The default for imperial units is 12", for metric it is 300mm. This setting is independent of the Run denominator.

• Offset Scale [decimal number]: This is the multiple of the text size at which the marker is offset from its edge or face so as to minimize z-fighting and overlap. The default value is 0.1.

• Text Scale [decimal number]: This is the multiple of the marker length used as the height of the label texts on a Slope Marker. The default is 0.15. This setting affects only Slope Markers. There is currently no support in the Overlay to specify Overlay text height though this may be added in a future update of the extension.

• Edge Marker Type [Triangle, Rise and Run Lines, Text]: The kind of marker that will be drawn if you click on an edge. The default is Triangle.

• Face Marker Type [Equilateral Triangle, Long Arrow, Short Arrow, Upright Triangle, Upright Rise and Run Lines: The kind of marker that will be drawn if you click on a face. The default is Equilateral Triangle.

• Text Label Format [Ratio, Fraction, Percent, Degrees]: The format used for text on a marker that supports combining rise and run into a single text string. Ratio is formatted as 1:12. Fraction is formatted as 1/12. Percent includes a single decimal place. Degrees follows the format specified in the model units.

• Rise of One? [true, false]: Calculate the run that corresponds to a rise value of 1 rather than using Run Denominator. For example, the same slope would display as 1:10 instead of 10:100 when the rise is 10 and the run is 100. The default is false.

• Min Slope [decimal number]: The minimum allowable slope, calculated as the value of rise/run (user must do the calculation, the input field can't parse expressons). Slopes smaller than this value will be colored magenta in both the Slope Markers and the Overlay. If it is set to <=0, the minimum is turned off. The default is 0.03, corresponding to a slope of 3%.

• Max Slope [decimal number]: The maximum allowable slope, calculated as the value of rise/run (user must do the calculation, the input field can't parse expressions). Slopes between the mininum (or 0 if minimum is disabled) and the maximum will be colored green. Slopes greater than the maximum will be colored red. If the value is set to <=0 the maximum is unlimited, effectively turning it off. The default is 0.08, corresponding to a slope of 8%.

• Batch Filter [edges only, faces only, both]: When either Slope Markers are drawn or entities are added to the Overlay monitor based on a selection set, this determines which kinds of entities are processed. The default is both.

• Overlay Display [both, colors, labels]: This determines how the Overlay draws its information on the screen. It can simply color faces and edges, add screen text labels, or both. The Cycle Label Choice item in the Overlay menu or Toolbar instantly changes between these display modes. The configuration setting is the default as SketchUp launches. The default is both.

• Mange Defaults [No Action, Save, Load, Reset]: The current values of the fields in the dialog are always activated in the extension when the user clicks the OK button. No Action means that nothing more is done with respect to user defaults. Save means the current set are saved as user defaults for the next time SketchUp is started. Load causes the current values to be replaced by the last saved set of user defaults. Reset causes the current values to be replaced by the extension's hard-coded defaults * for recovery if the user values have become garbled. The default is No Action.

Known Issues and Limitations

• As noted earlier, Overlay text labels bleed through objects that are closer to the camera. There may be no practical way to fix this until/unless the API adds support.

• There is currently no support to choose the label text size in the Overlay.

• The color choices are not user-configurable. Only three ranges are supported.

• The max and min values require user-calculation to get the values. This is trivial for percent slopes, but more awkward for degrees or rise and run.

• The Overlay works only on top-level groups and component instances. This was a deliberate limitation because probing deeper created large amounts of clutter and confusion about what nesting level the Overlay information was coming from.

2019-05-31 v1.0 Completed functionality, English only. Before publication, found and fixed a minor bug which sometimes didn't centre the run denominator on a zero slope. 2022-09-29 V1.0.1 removed some obsolete diagnostic output to the terminal 2023-07-09 V2.0 Added range coloring and Overlay V2.0.1 Fixed compatibility issues with pre-2023 Sketchup verions