Tutorial
This first tutorial highlights and describes the main features of RV2. This tutorial is intended to be a “quick start” guide of the main steps and procedures of the RV2 workflow. Specific parameters and optional features will not be addressed in detail. Further information about each of the procedures, methods and various optional parameters involved in each of the steps will be presented and discussed later in the week.
0. Intialisation
This first step initiates the RV2 engine, imports all the relevant packages and activates compas_cloud server. The startup window also provides various links to useful information, such as the online documentation, tutorials, tutorials and terms of use. By clicking “YES,” you acknowledge that you have read and understood the Terms and Conditions, and the Data Donation Agreement.
1a. Create Pattern
A Pattern is a collection of lines that define the topology of the form diagram. In this step, the user can create a Pattern from:
Rhino lines
Rhino mesh
Rhino NURBS surface (untrimmed)
skeleton
triangulation from boundary curves
quad mesh from boundary curves and point features
In this tutorial, we will use a simple orthogonal surface, which can be created through the Rhino command, “Rectangular plane: corner to corner.” By choosing two corners, create a planar surface that is a square in plan.
In the RhinoVAULT 2 drop down menu, select “Create pattern”, then “From Surface.” Select the the surface in the viewport.
This command will generate a Pattern from the input surface, using the UV mapping of the surface. The user has the option to enter values for “U” and “V.” For this tutorial, we keep the U and V to their default values of 10.
1b. Modify Pattern
RV2 provides various mechanisms for modifying the geometry of the pattern, such as moving vertices, changing attributes of vertices and edges, smooth and relax. These features will not be used in this tutorial.
2. Define Boundary conditions
Once a Pattern object has been generated, the boundary conditions will need to be defined. In RV2, the boundary conditions include: 1) identifying the supports (vertices of the structure where reactions are allowed); 2) defining and updating the openings; and 3) loading parameters and conditions.
2.1. Identify supports
In the RhinoVAULT 2 drop down menu, select “Define Boundary Conditions”, then “Identify Supports.”
The command will provide two options, to select or unselect vertices to define them as supports or not. Click 'Select'.
In this tutorial, we use the mode ByContinuousEdges, and select one edge on the left boundary and on edge on the right boundary of the pattern. Once the two edges are selected, press Enter, then all the vertices along that boundary from corner to corner, will be automatically selected (supports are shown in red).
2.2. Update boundaries
The second step of defining boundary conditions involves updating the geometry of the openings. In this tutorial, the two boundaries at the top and the bottom are the openings (the edges are on the boundary of the pattern but have no support vertices along them).
Because openings have no supports (i.e. reaction or external forces), they cannot be straight; openings need to curve inward towards the center of the pattern, so that horizontal equilibrium can be resolved.
In the RhinoVAULT 2 drop down menu, select “Define Boundary Conditions”, then “Update Openings.”
If there are straight openings found in the pattern, an automatic sag of 5% of the span of the opening will be imposed. Per opening, the user has the option to enter a desired amount of sag, as a percentage of the span of the opening.
In this tutorial, sag of 10% is applied to opening 1, and sag of 20% is applied to opening 0.
3. Create form diagram
Once the boundary conditions have been defined, the Pattern can now be converted into a FormDiagram.
In the RhinoVAULT 2 drop down menu, select “Create FormDiagram.”
If the creation of FormDiagram is successful, it will be displayed with green vertices and edges. The ThrustDiagram is also automatically created (displayed in light green), the geometry of which is equivalent to the FormDiagram at this initial, vertically un-equilibrated state.
4. Create force diagram
Once the FormDiagram has been created, the ForceDiagram can now be created.
In the RhinoVAULT 2 drop down menu, select “Create ForceDiagram.”
The ForceDiagram will be automatically drawn to the right (+x) of the FormDiagram. The initial ForceDiagram is the topological dual of the FormDiagram. The two diagrams are not yet reciprocal, meaning that the corresponding edges in the diagrams are not perpendicular to the other.
When the diagrams are not yet reciprocal (in other words, not perpendicular-ised or “equilibrated”), the edges with angle deviations above the defined angle tolerance will be displayed. The dots displaying the angle deviations are visual cues for the user, indicating that horizontal equilibrium has not yet been resolved.
5. Horizontal equilibrium
Once the FormDiagram and ForceDiagram have been created, the horizontal equilibrium algorithm perpendicular-ises either or both diagrams, which converts them from dual to reciprocal diagrams.
In the RhinoVAULT 2 drop down menu, select “Horizontal Equilibrium.”
Under “Alpha” option, the user will be able to select a value that determine which of the two diagrams will have more weight during the perpendicular-isation process. Default is “form100,” which only allows the ForceDiagram to update in its geometry. User can also enter the number of iterations. Default number of iterations is 100.
If horizontal equilibrium has been found, meaning that all the corresponding edges now have angle deviations that are below the defined angle tolerance, the two diagrams should no longer have any dots displaying the angle deviation values, as shown below.
6. Vertical equilibrium
With the FormDiagram and ForceDiagram now reciprocal, the coordinates of the ThrustDiagram can be iteratively computed based on a desired z-max (target height) value.
In the RhinoVAULT 2 drop down menu, select “Vertical Equilibrium.”
The user can manually enter a desired value for the target height of the vault, and the number of iterations for the algorithm. Default number of iterations is 100.
If the vertical equilibrium is successfully computed and found, the new ThrustDiagram will be displayed, now with updated z coordinates.
Settings
Under “Settings,” various global parameters and visualisations options can be modified.
Visualisation
There are several features that facilitate analysis and enhance visualisation.
In Settings > RV2 > show, checking "Forces" draws the edges of the ForceDiagram with a color gradient from blue, green to red, based on its the length (the horizontal force in the corresponding edge of the ThrustDiagram). The corresponding edges in the FormDiagram are also displayed with the same color, which makes the two diagrams much more legible and discernible (blue means smaller horizontal force, red means greater horizontal force).
With “Display Pipes,” the edges of the ThrustDiagram can be visualised with pipes, the radii of which are proportional to the internal forces.
Important functions
During the RV2 workflow, there may have been unintended modifications to the geometry of the diagrams, such as accidentally moving the vertices. In such cases, running the RV2redraw command will simply redraw the three diagrams without executing any command.
When a work session has ended, and the user wishes to start a new file/design, RV2clear_all command will delete all existing diagrams in the work session.
Loading and saving .rv2 session files
During any stage of the RV2 workflow, the three diagrams can be saved as .rv2 files. These files can be opened in the future, and the user can resume working with existing diagrams and resuming work where the user left off during the last session.
Last updated
