Preparing Files for a Site Model: Unfolding
|Using a digital model to prepare cut files for a physical site model using the UNFOLDING method. Involves the Explode and Rotate3D commands, or the UnrollSrf command.|
For this workflow, we will be working on unfolding the buildings. The ground surface cannot be unfolded because it has doubly curved surfaces, so we will only focus on the buildings. However, we will make TWO SETS of cut files for the building--one set for a physical model made out of paper , and once for a physical model made out of 1/16" chipboard. Both physical models will be at 1/8" = 1'-0" scale .
Before starting to prepare cut files, there are several steps to take.
Scale the Model
Use Save As to save the Rhino file as a separate file. This file will be used only for the preparation of files for physical modeling. Then, make sure no layers are locked and that no objects are hidden. Use the SelAll command to select all objects, and scale it to 1/8" = 1'-0".
The ground surface has already been prepared for you using this workflow . The ground surface is now a closed polysurface (instead of a floating plane) and is ready to model. However, since we will not be tackling the ground surface in this workflow, turn this layer off .
Unfolding the Buildings - Paper Model
The quickest way to unfold buildings is to use the UnrollSrf command. However, this command is not perfect, and often times we have to manually perform the same action using the Explode and Rotate3D commands. Since these cut files are for a model made out of paper, we do not need to worry about material thickness, since paper itself has negligible thickness.
Think about where you want the glued seams of the buildings to be versus the folded seams. Don't forget that the linework can be manually edited after the UnrollSrf command is performed. Use the labels to move and rotate individual surfaces.
In many cases where the object is complicated and/or has many individual surfaces that make it up, the UnrollSrf command will not work perfectly. The resulting linework may have multiple overlapping edges, which makes it impossible to cut out. In these cases, there are two options to proceed.
Split the original polysurface into smaller sections by using the Explode and Join commands. Then unroll these sections individually using the UnrollSrf command. Remember to label which edges will be joined, so you don't lose track of the pieces.
Explode and Rotate3D
Arranging Cut Files
Arrange the unfolded building surfaces in a row. Use the Text tool to label each object so keep track of the pieces. Keep the labels on a separate "text" layer so that they can be turned off later if needed.
Accounting for Material Thickness
Now that the first set of cut files for the paper model is complete, Copy the set over to the side. We will now edit this second set of cut files for a model that is made of 1/16" chipboard.
For glued corners, this will allow one piece to cleanly butt up against the other piece. It does mean that one edge of the material will show at each glued corner, but this is much easier than attempting to chamfer the corners (cutting both pieces at an angle so the outside edges line up perfectly).
For folded corners, you will also see (most of) a material edge, but these seams are often preferable to glued seams because everything lines up cleanly (since the pieces are still attached). It also speeds up the time it takes to build the model.
For this process, it will be helpful to use the Trim and Move commands to edit the linework at each seam. Be methodical about starting at one seam and working your way through the rest of the object's seams, so that you do not miss any.
Save the final result as a Rhino file (.3dm) and upload to your bSpace dropbox by the end of section.