There are various techniques you can use in ArchiCAD to distribute elements along a path. One example could be a tree object that is distributed at every 3000 millimeters along the side of a road. Let us see some scenarios.
Distributing along a curve
Let us say that you have a curve and you want to distribute Trees along it with a Tree at both ends.
If you want to place 11 Trees at even distances along the full length of the curve, then select the Tree object at one end, and use the Multiply command
Choose the “Rotate” option, set “Number of Copies” to “10”, and select the “Distribute” radio button. Then click “OK”.
Make the center of the Arc the center of rotation, with the center of your existing Tree the beginning of the Rotation Arc and the other end of the Arc the end of the Rotation Arc.
This placement method is also possible if you already have your objects placed on the Floor Plan. In this case select all Tree objects (all 11 of them) and use the Edit\Distribute\Special Distribute command.
In the Distribute Dialog, select the “Bounding box anchor” radio button and the middle anchor option, plus select the “Click an existing line or element edge” radio button, then click “OK”.
Finally, click the Arc along which to distribute them.
The Tree objects are evenly distributed along the Arc.
Distributing elements at specified distances
If you want to distribute these elements so that they are at specified distances form each other, here is how to do it.
Let us say you want these Trees to be 3000 millimeters from each other. Draw a circle with a radius of 3000 millimeters from the end point of the Arc where the center of the first Tree object is located.
Select the Tree object and use the Multiply command. Choose the “Rotate” radio button for action. Choose the “Increment” option for placement. For “Number of copies” choose a large enough number so it will cover the whole length of the Arc. Then click “OK”.
Note: If you create a radial length dimension for the Arc, you will see its total length. In our case it is a bit more than 33 meters so we will need 12 copies.
To create the copies, make the center of the Arc the center of Rotation, with the center of the Tree being the start of the Rotation angle and the intersection of the Arc and the 3000 millimeter circle being the end of the Rotation angle.
After deleting our auxiliary circle and dimension plus Tree copies that do not fall on the Arc we have our desired result.
Note: Of course most of the time the last Tree object will not be exactly at the end of the Arc.
Note: with this method the centers of the Tree will be at a distance of 3000 millimeters. Measured along the Arc, they will be at slightly longer distances (radial length dimensions are on the outside of the Arc in the illustration).
If you want the 3000 millimeter to be measured along the Arc, you will need to use other techniques outlined below.
One technique is to calculate what radius the auxiliary circle must have so that the Arc segment length will be 3000 millimeters. In our example it is 2998 millimeters so if you use such a circle the result will be 3000 millimeter distance between Tree centers along the curve of the Arc.
Another method is to use Special Snap Points. Let us consider now a Spline along which we want to distribute these Trees (the method works similarly for Arcs). We want to use “Distance” type Special Snap Points for the placement of these objects. So let us set Special Snap Points to “Distance”.
Also, let us go to the Set Special Snap Values Dialog and specify “3000” for Distance, then click “OK”.
Now select the Tree at the end of the Spline and activate the Drag Multiple Copy command.
Hover your cursor above the Spline near its end and the Special Snap Points appear at 3000 millimeter intervals. Click the first Special Snap Point to place the first copy.
When you place the copy, the Special Snap Points disappear. So move your cursor upward a bit along the Spline and they reappear. Continue placing the copies along the Spline until you arrive at approximately the middle of the Spline.
There is something to know about how this Distance option works: it always starts drawing the Special Snap Point from that end of the element that is closer to the point where your cursor is above the element. So when the cursor is above the left side of the Spline, Special Snap Points are drawn from the left end. When it is above the right side of the Spline, they are drawn from the right end. Notice how Special Snap Points appear at different positions depending on where I place my cursor above the Spline.
So when you get to the right side of the Spline, you either always move your cursor back to the left side so the Special Snap Points appear correctly, or use the following trick: Activate the Line Tool, hover your cursor above the left side of the Spline, then draw a short Line segment originating from the rightmost Special Snap Point on the Spline.
Now select the “Between Intersection Points” option of the Special Snap Point menu palette.
After this when you hover your cursor above the right side of the Spline, the distances will start from the nearest intersection point (that of the Line we have dawn and the Spline), which is located at a Special Snap Point. This way the Special Snap Points will always be located at the same positions regardless of whether they are measured from left or right.
Continue placing the copies until all instances are placed. Obviously the last instance will be at the intersection of the auxiliary line and the Spline. Then delete the auxiliary line.
Note: The Special Snap Points method will work on any Spline that is a single element. However in case of Polylines the Distances are measured separately on each segment of the Polyline. A you can see, Distances are displayed only for one segment (the segment hovered over) of the below Polyline, not continuously on all segments.
You can read more about this on Facebook