Make Solid From Surfaces

This command creates a solid model using TIN surfaces for the roof and floor plus 3D perimeter polylines. This method for creating a solid model applies when there are survey points on the roof, floor and walls.

The TIN surfaces can be prepared with routines like Triangulate & Contour in the Civil module. In Triangulate & Contour to build the roof surface, turn on the option to Write Triangulation File and select the roof points. Then repeat Triangulate & Contour to build the floor surface by selecting the floor points.

The 3D perimeter polylines represent the walls of the solid and should have elevations between the floor and roof. If there are survey points on the walls, these can be connected into 3D polylines by using commands like Draw 3D Polyline. Multiple 3D polylines can be used to create the solid model. 3D polylines that are inside other 3D polylines are used as exclusion areas for the solid model and create holes in the model.

To build the solid model, the program connects the 3D polylines to the roof and floor surfaces.

3D rib polyline and survey points
3D view of solid model

Prompts

Top Surface To Read Select TIN file
Bottom Surface To Read Select TIN file
Select rib polylines.
Select objects: pick 3d polyline(s)
Solid File To Write Select MDL file

Example Workflow

This example uses survey point data to build the solid by creating the rib 3D polyline and top and bottom surfaces.

Step 1: Import Points

From a new drawing, run Points > Set Coordinate File and select a coordinate file named sample_solid.crd from the Carlson Projects folder.

To have the points drawn at a good size, run Settings > Drawing Setup and set the Horizontal Scale to 10 and the units to English.

Next run Points > Draw/Locate Points and turn on the option to Layer By Description and then pick Draw All. In this example, the points have different description codes to identify roof, floor and rib points.

Step 2: Draw Rib 3D Perimeter Polyline

There are two codes of "R" and "P" for points on the perimeter. To view only the perimeter points, run View > Isolate Layers and pick on a point with a "R" description and a point with a "P" description.

Next run Draw > Polyline > Polyline By Nearest Found. Set the type to 3D Polyline, the max separation to 5 and the layer to RIB_PERIM.

Then choose the Screen selection mode and then select all the points.
Select point from screen or by point number [<Screen>/Number]? press Enter
Select points.
Select objects: all

The Polyline By Nearest Found connected the points except for the large gaps. To create a single closed polyline and span these gaps, run Edit > Join Nearest. Set the max separation to 100 and the method as Directly Connect Endpoints.
Then select all the polylines to be connected.
Select lines, arcs and unclosed polylines to join.
Select objects: all

Step 3: Draw Top and Bottom Perimeter Polylines

To use for building the top and bottom surfaces, the next step is to create top and bottom 3D perimeter polylines. First, turn all the points back on by running View > Restore Layers.

The bottom points have a description of "S". Run View > Isolate Layers and pick on a "S" point.

To elevate the perimeter polyline at the bottom surface, a grid file is a good way to extrapolate the bottom points to cover the perimeter. Run the Surface > Make 3D Grid File command from the Civil module. Set the file name as bottom.grd. In the options dialog, set the method as Inverse Distance and the grid position as Screen Pick.
For the grid corners, pick a large window around the points to generously make an area large enough to cover the perimeter.
Pick first grid corner: pick the lower left point
Pick opposite grid corner: pick the upper right point
Select points, lines, polylines and faces to grid from.
Select objects: all
Reading points ... 29
Use inverse distance to which power [First/<Second>/Third/Other]? press Enter
Use elliptical inverse distance [Yes/<No>]? press Enter

Now that we have this bottom surface, we can create a bottom 3D perimeter polyline. Turn on all the layers again by running View > Restore Layers. Then run 3D Data > 2D to 3D Polyline > By Surface Model from the Civil model. Choose the bottom.grd as the surface to process. Pick the rib polyline as the polylines to convert. Be sure to answer YES to the Keep Existing Polyline prompt. Set the layer to BOT_PERIM.
Select polylines to convert.
Select objects: pick the rib polyline
Use current polyline elevations as vertical offset from surface [Yes/<No>]? press Enter
Keep existing polylines [Yes/<No>]? Y

Step 4: Create Top and Bottom Surfaces

The data is prepared and now the surfaces can be created. Let's build the bottom surface first. Since the perimeter polyline for rib, top and bottom are on top of each other, it is tricky to select them individually. Run View > Layer Control and freeze the layers for RIB_PERIM and TOP_PERIM. Then run View > Isolate Layers and pick on a "S" point and the bottom perimeter polyline.

Step 5: Create Solid Model

We need to view the rib perimeter polyline for creating the solid. Run View > Layer Control to thaw the RIB_PERIM layer and freeze the TOP_PERIM and BOT_PERIM layers.

Finally, run Solid > Make Solid From Surfaces. Select the top and bottom surfaces created in step 4 and the rib polyline created in step 2. Then specify the solid model file name to create.

Top Surface To Read Select TOP.TIN file
Bottom Surface To Read Select BOTTOM.TIN file
Select rib polylines.
Select objects: pick rib polyline
Solid File To Write Enter a file name

Pulldown Menu Location: Solid
Keyboard Command: make_solid
Prerequisite: 3d perimeter polyline and two surface files