Tutorial1_Bathtub

BLOCKRANGER TUTORIAL NO. 01: BATHTHUBOBJECTIVEIn this tutorial you will learn in detail how to build a quality block-structured hexahedral mesh from a CAD model described by a DXF file, the reference model. To create a mesh using BlockRanger, you must create an assembly of 6, 5 or 4-sided Rhino solids that conforms to the reference model. The creation of such an assembly is the objective of this tutorial. The reference model is shown below, left. The final hexahedral mesh is depicted below, right.PREPARATION1. Start Rhino and select Large Objects, Meters as your template. If Rhino does not ask you for a template, File|New and select Large Objects, Meters.2. If you have not already done so during an earlier work session, drag the content of Rhino5 Stuff onto your Rhino5 window to install the plug-ins, menu items and icons contained in that folder in Rhino5. Another installation option is to double-click the BlockRanger.rhi installer file to install the plug-in and the associated tools. The installation is permanent and you will not need to do this for later sessions. 3. in Rhino, type SetWorkingDirectory and navigate to the your current working directory. In this fashion Rhino knows where to read, import from and save files.IMPORTING THE GEOMETRY1. File|Import Bathtub.dxf, and if you are asked about the model units, enter meters. Enter millimeters for the layout units. You can hide the construction plane grids in all the viewports by clicking on the Options icon to open the Rhino Options dialog box. In the left pane, in Document Properties, select Grid and turn Show grid line and Show grid axes off.2. Select the reference model, which is a mesh of triangles, and Edit|Layers|Change Object Layer. In the Layer for objects dialog box, click on New, and in the New Layer dialog box enter reference. Click OK, and OK again to finish moving the mesh to the reference layer.3. Click on the Edit Layers icon to open the Layers pane to the right of your Rhino window. In the Layers pane, click on the black square indicating the current color of this layer and select Aquamarine to change the color of this layer to aquamarine.CHOOSING THE RIGHT MESH BLOCK LAYOUT FOR YOUR MODELBlockRanger processes a layout of solids into a layout of mesh blocks or primitives . The present model may be decomposed into solid blocks in many ways. Below are 5 different Rhino solid layouts (left) and the resulting mesh blocks (right) for the same problem. In this tutorial you will build the last layout which is composed of eight six-sided solids. BUILDING REFERENCE CURVESKeeping the last layout in mind, you will build curves that will become edges of solids. While Rhino refers to single surfaces as a Surface and composite surfaces as a Polysurface no such distinction is made when it comes to curves. Single and composite curves are both referred to as curves in Rhino, but for the task at hand, the distinction between single and composite curves is important. Single curves are such that when they are Edit|Exploded, they result in a single curve. In this tutorial, you will build single curves only.1. Click on Osnap (Object Snap) at the bottom of the screen to highlight it. Make sure that End, Near, Point, Mid, Cen, Int, Perp, Tan, Quad, Knot and Vertex are checked, as shown below. Grid Snap may be turned off.2. Curve|Arc|Start, Point, End and Zoom in around the point shown below and click on the corner vertex to set the Start of arc (Below, left). Following along the upper curved edge of the bathtub, click on a second vertex along the curved edge of the tub (center). For the last point, click on a vertex so that the resulting curve is approximately a eighth of a circle fitting the edge of the curved mesh (below, right). For complex curves, InterpCrv (Curve|Free-form|Interpolate Points) may be used. Essentially, any curve tool in Rhino is acceptable as long as it produces single curves, i.e. when exploded, it results in one curve.3. Build a second eighth-circle starting at the vertex you finished the last arc with, and ending at the vertex where the curved edge joins the straight edge of the bathtub (below, left). Curve|Line|Single Line to build a straight line joining the demarcation between the two curves to the corresponding vertex at the floor of the tub. Build a 3rd and 4th arc representing two eighth circle curves bordering the floor of the tub (right). 4. Curve|Line|Single Line to build two lines joining the ends of the arcs. 5. Curve|Line|Single Line to build several lines joining the corners of the reference model.6. Turn the model over and Curve|Line|Single Line to build to outline the remaining feature edges of the reference model (below, left). Hide the reference layer by clicking on the light bulb next to it leaving only the curves you have created (right).7. Select the curves representing the bottom of the tub (highlighted below, left), Transform|Copy, click on corner marked A, then corner B, then to build a copy of these curves flush with the lower surface of the reference model (right). 8. Curve|Line|Single Line to build the vertical lines show below (left). Use Curve|Line|Single Line to build line segments starting at given points and perpendicular to target lines. Note that the word Perp. pops up as your line segment approaches a target line (right). 9. Finally, Curve|Line|Single Line to build these last linesBUILDING THE FIRST SOLID1. Select the two curves highlighted below, left, Surface|Loft, use the settings shown below and click OK to build a lofted surface between the two curves. Similarly, build the surface opposite the previous surface with the lines highlighted below, right.Note that the flat rectangular surface could have been created using EdgSrf, PlanarSrf or Lofting in a transverse direction.2. Select both surfaces, Curve|Curve from Objects|Duplicate Border (below, left). While the two borders are highlighted, Surface|Loft. 3. Note that Rhino responds with: Drag seam point, and the Loft preview indicates that Rhino will connect the red vertex with the green one (below, left). This would result in a twisted lofted surface. To force Rhino to connect the red vertex with the blue one instead, click on the green vertex, then on the blue one (right). 4. Hit and the Loft Options dialog box opens. Make sure that Straight sections and Do not simplify are selected (below, left), and click on OK to complete the loft operation (right).5. Delete the borders that remain highlighted. You now have the two initial surfaces and a polysurface resulting from the lofting of their borders. Select the two surfaces and the polysurface and Edit|Join to complete the creation of your first solid.The last 5 steps represent the sequence of operations that you will use to build the remaining 7 six-sized solidsBUILDING THE REMAINING SOLIDS1. Select the next two eighth circles and build the lofted surface between the two. 2. To build the opposing surface, note that the two line segments highlighted below need to be split at the points marked with the blue circles (below, left). To do so, select one of these lines, followed by Edit|Split. Rhino asks for the cutting objects. Click on the option Point, then click on the highlighted line at the location marked with the blue circle, followed by to complete the splitting operation. Similarly, split the second horizontal line. Now that the lines are split to size, select the two horizontal lines, Surface|Loft and OK.3. Select the opposing surfaces, Curve|Curve from Objects|Duplicate Border, and while the two borders are highlighted, Surface|Loft. 4. Again, the Loft preview indicates that Rhino will connect the wrong corners (below, left). Click on any of the two white points at the ends of the guide line connecting the two surfaces, then click on the appropriate surface corner to correct this (right). 5. Click OK to complete the loft. Delete the highlighted borders. Select the two surfaces and the newly created lofted polysurface and Edit|Join to complete your second solid (below, left). Complete your third solid in the same fashion (right). 6. Turn the model over and use Surface|Loft to build the surface representing an eighth cylinder located under the floor of the tub (below, left). Build the opposite surface and used Surface|Loft again to complete your fourth solid. 7. For the fifth solid, build the cylindrical surface first. In attempting to build the opposite surface note that the lower line needs to be split (below, left). Line|Single and draw a line starting at the end of the shorter of the two and perpendicular to the longer one (right). 8. Follow the same procedure and complete the fifth and sixth solids.9. Two solids remain to be built. The quarter cylinder located below the floor of the tub can be built using the same procedure. Select the 4 curves surrounding the base of the quarter cylinder (below, left). Note that the longer segment needs to be split. Unselect everything, select the long segment, Edit|split, click on the option Point, and click at the center of the quarter-circle representing the base of the solid you intend to build. Now that you have 4 curves, Surface|Edge Curves to create the surface spanning between the 4 curves and delete the curves (right). 10. Use EdgeSrf, Loft or PlanarSrf to build the rectangle next to quarter-circle you just created (below, left). Select both the quarter-circle and the rectangle, Solid|Extrude Surface|ALong Curve and click on any of the vertical line segments adjacent to these two surfaces (near its lower end) to build solids 7 and 8 simultaneously. Delete the two surfaces that have remained highlighted. The two resulting solids are highlighted below, left. 11. Your solid model is now complete.VERIFICATION AND CLEANUP1. A to select everything in your model (below, left). Rhino should respond by 8 polysurfaces, added to selection + a number of other items. If a number of surfaces appear in the list, this is an indication that as you were building the solids, you did not Join certain surfaces into solids. Find them and join them so that you have 8 solids. 2. Select all 8 solids (by clicking on them or using Edit|Select Objects|Polysurfaces) and Edit|Object Properties (F3). The Property dialog box indicates that the selected polysurfaces constitute 8 closed polysurfaces. Again, if any of the polysurfaces is not a solid (meaning closed polysurface), identify them and join them into solids.3. Hide all solids and delete everything else (essentially mostly curves). Unhide everything (right-click on the light bulb icon) to recover all your solids. You model now contains only solids. 4. Select the 3 upper solids and Edit|Layers|Change Object Layer. When the Layer for objects dialog box opens, click on New, enter Upper solids in the New Layer dialog box, click OK, followed by OK, again in the Layer for objects dialog box to complete the moving of the selected solids to the Upper solids layer. Similarly, move the remaining lower solids to a layers named Lower solids. 5. If the Layer pane is not open, click on the Edit layers icon to open it. Click on the black square next to the Upper solids layer and when the color chooser pops up, select the Gold color. Similarly, set the color of the Lower solids layer to Lavender.RUNNING BLOCKRANGER1. Select All solids, and click on the Hex meshes from solids icon: , or just type BR in