Creating the body of a Maserati Birdcage 75th

From WikID


The following tutorial walks step by step through the modelling process of a Maserati Birdcage 75th body. In short, most of the modelling work was done using T-Splines to optimize the body. Towards the end of the process, the model is converted to a Rhino NURBS model in which the last Rhino commands are used to complete the car. The tight integration of T-Splines with Rhino made this workflow more efficient so that within an hour the body already has a nice shape. The wheels are left out of this tutorial, but there are plenty of tutorials to make car wheels available on the internet.

Note: Many hotkeys are used in this tutorial, so make sure these are set on. When the hotkeys are turned on, the typing of t-splines and rhino commands can only be done when the mouse is on the command line. Otherwise hotkeys are being used.

Also before starting the tutorial some pictures (or even better, some blueprints) of the front, back, side and top view of the car are needed.

The body


1. Start the PictureFrame command (Surface toolbar > Planes > Picture Frame, or type PictureFrame). You will see the File Open dialog as Rhino sends you off to locate the image you wish to use. Once the image is selected, you will be prompted to place the plane as in the Plane 3Point command, with a Vertical option.

Note that the plane can be any size but is constrained to being of the same aspect ratio as the image. The first point picked for the plane corresponds to the lower left corner of the image, the second to the lower right and the third pick places the top edge.


2. Do it again for the other 2 views and try to place them in the right dimensions. When not sure if the pictures have the same size use the Polyline command to draw straight lines to use as guidelines for the other pictures.


3. Now turn on the T-splines plugin by using the tsEditMode command or press the green on/off button in the T-splines toolbar or press Ctrl+Space.

4. Make faces that cover the side of the car by using the Append face command or type tsAppend. With this command rectangular shapes can be made which will represent the faces of your car. Try to make the global shape and not every detail of the car already. This can easily be added afterwards. Every face needs to be in line with the rest of the faces to create a smooth surface.


5. When finished with the faces go to Front view and select the T-splines Mesh and drag it to the right side of the car.

Note: Turning on Ortho (F8) or holding the Shift-key while dragging the mesh makes sure the movement will be horizontal.

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6. Use the Bend tool of rhino to bend the straight mesh nicely around the curvature of the car. First do one side of the curve and then do the other.

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7. Do the same thing in the Top view


8. From the Transform menu, click Mirror and choose the Y-axis as the Start of the mirror


9. Use the Bridge tool in T-splines (tsBridge) to connect the 2 meshes together. In Select face group(s) to bridge, click on Faces to choose edges that you want to connect.

10. Click twice on the same top edge of 1 of the meshes to choose the whole line of edges and do it also with the mirrored mesh.

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11. Choose the amount of segment that you want to bridge between the meshes. I used 4 segments to have enough faces and edges to control the model.

12. Repeat the previous 2 steps with the front and the back curves to connect it all together.


13. To close the gaps between the bridge go to Vert mode (press the A-key) to be able to select the points of the model.

14. Select the 2 points close to each other that need to be connected and Weld them together by pressing the letter Z. Try to select the 2 points at the same time, because when selecting them separately the second point will move towards the first point.

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15. Hide the pictures and continue with the rest of the points till only the bottom side of the car is open.


16. For a smooth and symmetric model we have to turn on the Symmetry mode in T-splines. So press the feature and select the model. Press Discover to let T-splines make the symmetry line. In Select Symmetry type, choose Axial and select 1 of the edges in the middle of the car. At this edge a green line, the symmetry boundary, has appeared.


17. Press S-key to go into Edge mode. In this mode try to move edges till they are lying in the same line. This will ensure that the model will be very smooth without any small bumps. Also lift up the middle of the car so that it corresponds to the shape of the car in the pictures.

Note: Use the L-key after selecting an edge to select the whole line of edges. This makes it easier to move lines. Use this in combination with the Scale feature of T-splines (press the R-key) to straighten the line in 1 movement.

To move lines or points or faces not only horizontal or vertical but still in only 1 plane, use the grey circles near the translate arrows.


18. After making a nice curved shape try to make the bumps in which the wheels are going to be put in. Try to switch between Box mode and Smooth mode to see the real result by pressing the Tab-key.

Still, make sure that all the lines are parallel to each other, so that it will result in a smooth surface.

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The wheel wells

19. Unhide the pictures again and turn to Faces mode (press the D-key). Delete the Faces that are in front of the wheel.


20. Draw a Circle on top of the wheels and manipulate the control points by pressing the F10-key. Try to match the Circle with the wheel well in the car by moving the control points.


21. Then draw a Polyline to Trim the bottom of the circle, so that it stops at the same points as where the car ends.

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22. Go to the Front view and move the curve to the outside of the car. Now use the Bend tool to nicely bend the curve till it matches your shape.


23. Go to Perspective view and count the amount of faces of the car that are around the wheel curve (in my model it are 8 faces). Now click on the Curve again and use the Rebuild command to change the amount of control points in the curve. For the Point count choose the amount of faces and add the Degree listed below the point count to this number (so with 8 faces around the wheel curve and a degree of 3, the point count must be 11).

24. Now use the Scale feature in T-splines (press the R-key) in combination with the Alt-key to scale and extrude the curve for just a tiny bit with the grey rectangle on the scaling feature to create a small mesh.


25. As you can see the small extrusion has the same amount of faces as the shape around the wheel well, which means that it is possible to connect the two surfaces together. So select the Bridge feature and select all the edges that need to be connected. Press Enter and notice that the symmetry now is lost in the model. You do not have to fix it yet.


26. Repeat the same steps with the wheel at the end of the car.


27. Now we can fix the symmetry by Deleting 1 whole side of the car of which the wheel wells are not added.


28. Press the Symmetry feature, select the model and click on Add to mirror the model. Click on Axial and draw a line on top of the Y-axis. Make sure that the Grid Snap is on to draw a line which is perfectly on the Y-axis.


29. Notice that the green line does not appear. This is caused by the mirrored surface is interfering with the other surface and both are lying a bit on top of each other. To fix this go into Vert mode (press the A-key) and Weld (by pressing the Z-key) the small points that are overlapping each other together, separately. Now slowly the green line comes back.


30. Again the edges of the car can be put in line of each other when necessary.


The bumpers

31. For the grill on the front side of the care, we need to add more lines. So select a row of lines in the Front view.


32. Use the Insert Edge (simple) tool to insert an extra line above and below the current line (click BothSides on to do it in 1 time).


33. Switch to Face mode and select the face that are just created and Alt-drag them inside the car. First Alt-drag it just a few millimetres to create a sharp edge, then Alt-drag it again a few centimetres and then a few centimetres further again.


34. Use the Scale tool in T-splines to straighten the faces and also the first row of lines in front of it.


35. Again, you can change the lines to make it more smooth, and make nice shapes of the grill


36. To change the shape of the grill extra edges or points can be add. To make the triangle shape on top of the grill 2 edges can be added. Select the 3 edges shown below that need to be pulled down. To make a sharper edge in the grill extra edges are needed. So use the Insert Edge (simple) and click on BothSides to turn it on. Inserted edges close to the current edges to make sharp edges.


37. Turn to Box mode and move the first 2 edges down with the blue arrow till the preferred height. Turn to Smooth mode again to see the result.


38. Try to change the rest of the grill too, to let it match your preferences.


39. To create the front, back and side bumpers the same method as used from steps 31 till 36 can be used.

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40. In the meantime the inside of the wheel wells have been made. Alt-drag all the edges of the wheel well (select 1 edge and press L) inside the car 3 times, and use the grey square of the Scale tool to almost close the wheel barrel.

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41. Bridge the edges together to close it and use the Scale tool to straighten the inside faces again.

42. Now that everything is modelled the T-splines mesh can be converted to a Rhino NURBS model, with the button next the T-splines on/off button.


The roof

43. Go to Top view, Unhide the pictures, and put the view on Wireframe to see the pictures.

44. Use a Curve to duplicate the roof of the car and Project it on top of the car


45. With a Split feature the roof and the car can become separate parts and can be changed to its preferred place.


46. Use a Bend tool to put the front of the roof a bit lower and Scale (Transform > Scale > Scale-3D) it to make a small part line between the roof and the rest of the car.


47. With a Blend Surface (Surface >Blend Surface) the gap can be filled. Now select one of the edges of the roof and select All in the command line. Press the Enter-key and select an edge of the car, and again select All. After pressing Enter, choose the Position option for both 1 and 2 to create a straight blend.

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48. Select all the parts and Join them together.


Finishing the model

49. The model can now be closed by using a Patch (Surface >Patch). Select all the curves at the bottom of the car.

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50. The side spoilers are made out of only 1 Sweep. First sketch on the Right view the shape of the spoiler with a Curve. Then sketch the rail in the Top view. You can use a Bend to adjust the rail so that the spoilers come out perfectly.

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51. Use the Sweep 1 rail (Surface > Sweep 1 rail) to create the spoiler and use a Boolean Union to join them both together.


52. Now you can add details if you want or make wheels with the help of other tutorials.

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