Modeled & Rendered by Daniel Ljunggren

1，Modeling a Brachiosaurus

This tutorial is the most basic and easy-to-follow in Secrets of Rhinoceros, but it is still recommended that you have some experience with Rhinoceros before attempting it. The tutorials that come with Rhinoceros and information in the Rhinoceros manual are the best starting point for beginners who are new to the program. This tutorial describes how to build a Brachiosaurus in Rhinoceros, to produce models that could be used in a rendering as shown above. The tutorial includes a reference image to trace over, and sample files showing intermediate and final versions of the model, so it should be easy to follow. Please allow two hours to complete this tutorial.
As visual reference for this tutorial, load a picture of a Brachiosaurus, Brachio.jpg from the dino directory of the CD-ROM. Place the image in the Right viewport with the ’PlaceBackgroundBitmap’ command. Place the ‘First corner’ in the top right of the viewport and the ‘Second corner or length’ as close as the bottom of the viewport as possible. Then move it (‘MoveBackgroundBitmap’ command) to the middle of the viewport, positioned as shown below. If you have a grid visible in the right viewpoint, hide it with command ’ShowGrid.’ (You can just type ShowGrid at the command prompt and press enter.)

Using the picture as reference, draw an outline of the body of the Brachiosaurus. (Do not trace the legs and head for now - they will be modeled separately later.) Double-click on the viewport title of the Right viewport to maximize it, and draw two curves (InterpCrv command) of the outlines of the dinosaur as shown below.

Using the picture as reference, draw an outline of the body of the Brachiosaurus. (Do not trace the legs and head for now - they will be modeled separately later.) Double-click on the viewport title of the Right viewport to maximize it, and draw two curves (InterpCrv command) of the outlines of the dinosaur as shown below.

2， Modeling a Brachiosaurus: Adding The Middle Curve
The outline curves of the dino are only two-dimensional. A middle curve of the dino will become the first three-dimensional cross-section curve, beginning to define the dino's side.

Make sure ‘End’ Object Snap is on when making the start of the curve at the tail end. Using only the Right view, draw a middle curve something like this:

This middle curve still needs to be pulled outwards, to gain depth along the X axis. Select the middle curve, make the CV’s (Control Vertices, also known as Control Points) visible with PtOn, and move CV’s out from the middle as shown below. (To move points in Perspective viewport in one axis, hold Shift button as you move.)

Continue the fine-tuning of the middle curve from the Top viewport. In this step you might need to add some points (’InsertKnot’ command) to get a satisfying result. When finished it should look close to this:

Continue the fine-tuning of the middle curve from the Top viewport. In this step you might need to add some points (’InsertKnot’ command) to get a satisfying result. When finished it should look close to this:

Now you have the curves for a rough shape of the dinosaur body. The curves automatically stay selected after the CSec command, so you can use ‘Loft’ to skin them together. Execute the 'Loft' command, and in the ‘Loft options’ panel use the default settings, and hit OK.

Optional Notes:
Michael Gibson (one of the original Rhino developers) volunteered the following comments about optimizing the use of CSec after he read this tutorial. We are grateful to Michael for all of his feedback, some of which appears in the edited text of the tutorial.

4， Modeling a Brachiosaurus: Rounding the Surface

Use the ’Properties’ command to open the Object Properties panel. You can give the surface an appropriate color and highlight as seen below, or pick any other color you like.

Render the dino to see what the body looks like so far:

You can see that the shape of the surface is not round enough, and will need some more work. Before editing the surface, your scene can be made more manageable by putting the different objects into different layers. Use the ‘Layer’ command to see the layer panel.

In the Edit Layers panel, choose ‘New’, name the new layer to ‘Original curves’, and set it to ‘Off.’ Click OK.

Select all the curves in the scene with ‘SelCrv’, and then use ‘ChangeLayer’. Choose the ‘Original curves’ and the curves are moved into that layer and disappear from viewports (because the layer is set to Off.)

Now the surface can be edited by itself, without any risk of accidentally selecting the original curves. Putting curves away into another layer is preferable to deleting them, because you always might need construction curves again in unexpected revisions to a project, or in starting other models or projects.

In order to make the current body surface rounder (and more "Brachiosaurus-like"), you need to move the outer row of CV’s. Use DynamicShadingPerspective to see a shaded surface in Perspective viewport as you are editing. In the front viewport, zoom in on the end and move the CV’s until the surface looks more round, basically that means moving the CV’s until the cross sections looks like half of a circle for the tail and neck (the figure below shows the first curve rounded) and almost as round in the torso area. When moving CV’s in the neck area, use the Top viewport, and view your results in the Perspective viewport so you can get a good look on the surface from different angles. (NOTE: Don’t move any of the outer rows of CV’s off the central axis, because you will need to mirror the surface in order to make the full body later on).

The first cross section modified to a more rounded look, compared to the larger ones behind.

The figure below shows what it should look like after the CV manipulation. After this step, your scene should be similar to the sample file ’brachio2.3dm’ from the CD-ROM. (Show here with render wireframe activated.)

5， Modeling a Brachiosaurus: Starting the Head

To start building a head, begin with nothing else visible: Create a new layer called Body surface, and check ‘Off’ to make it hidden. Change the body surface to this layer (as was done with the curves on Page 4.). Hide the background in the Right viewport with ‘HideBackgroundBitmap’ command.

Make a sphere (‘Sphere’ command) in the Front viewport about the center of the axis.

To make the sphere more dense, use the ‘RebuildSrf’ command, and in the ‘Rebuild Surface’ dialog box use a point count of 12 in both directions. This will give you enough points to squash, manipulate, and reshape the surface by dragging selected CV's.

Rotate the sphere so the left end (seen from the Right viewport) is facing you in the Perspective viewport as shown below.

Make the CV’s visible with ‘PtOn’ and in the Right Viewport. As shown below, select the CV’s in the middle and pull them inwards as a start for the basic shape of the mouth. Use ‘DynamicShadingPerspective’ to see the shading while editing.

To make editing easier, select the CV’s shown below, and use ’HidePt’ command to hide the selection of CV’s. This will reduce the amount of visual clutter on the screen, and reduce the risk of accidentally picking points on the back of the surface when you are trying to pick points in the front.

Select the CV’s shown here:

Move the selected points outwards to make the shape of the jaws:

Make the hidden CV’s visible again with ‘ShowPt’ command, select them along with the CV’s of the jaws that weren’t moved, and move them to the left (seen from the Right viewport) so the back of the head becomes shorter relative to the overall shape:

The jaws are wide open, therefore select the CV’s highlighted below, and pull them down.

Select the CV’s on the lower jaw equivalent to the ones on the upper jaw and move those up. The result (shown below) should be similar to the sample file ’brachio3.3dm’ from the CD-ROM.

6， Modeling a Brachiosaurus: Completing The Mouth

To help better define the mouth shape, an extra isoparm needs to be inserted close to the mouth opening. Use ‘InsertKnot’ command in the Front viewport, enter U to choose the U direction, and place the isoparm as shown below. (The two directions of the isoparms on a sphere, U and V, are similar to latitude and longitude. Selecting U is important if you are making a curve that will run around the head instead of end-to-end.)

Select the CV’s that were created and in the Right viewport use ‘Scale1D’ command. For ‘Origin point’, place the marker in the center of the head, and then place the ‘First reference point’ as shown below.

Move the marker up (hold Shift for a straight line) until the space in the mouth has been scaled taller, as shown below.

In order to close the opening in the front of the mouth, select the CV’s shown below and pull them downwards (use 'DynamicShadingPerspective' to help better view your work).

In the Right viewport, move the CVs to the left to achieve a more rounded end of the mouth.

Do the same with the equivalent CV’s in the lower jaw, so you get the results something like this:

OPTIONAL: You may wish to edit the shape of the head by inserting more isoparms and dragging them to add extra detail, such as a ridge along the top of the head. How many, or how few, small details you add is really up to you. In modeling creatures that will be animated or rendered in other software, you may be able to add more detail later via texture mapping, bump mapping, or displacement mapping, so that you render realistic creatures while sticking with relatively simple geometry. Simpler geometry is usually easier to edit or animate than surfaces with large numbers of isoparms.

Use ’DynamicShadingPerspective’ when editing CV’s. Insert isoparms in areas where you can’t get enough detail you want with the current number of isoparms. It is up to you how you want your head to look, so move CVs and insert isoparms as you see fit to customize and improve the modeling of the head. If you want to add a ridge along the top of the head, you will probably want to insert at least 2 or 3 isoparms near the back of the head, and then show points and drag them upwards.

The sample file ’brachio4.3dm’ from the CD-ROM shows a head modified after this step.

After some CV manipulation, scaling and inserting isoparms in the proper areas the head is starting to take shape.

7 Modeling a Brachiosaurus: The Eye Area
Create a sphere for the eyeball, and place it as shown below.

In the Front viewport set Object Snap to ’Near’ and use the ’Mirror’ command to have an eye on the opposite side of the head.

It is necessary to position the eyes before doing the eyebrows, because the position of the eyeballs will be used as reference for the eyebrow position.

The area around the eyes needs more detail. Insert an isoparm as shown below, don’t forget to make it symmetrical.

NOTE: To insert symmetrical isoparms in a closed surface requires that the seam be located along the plane of symmetry. You can use the ShowEdges command to visually highlight the seam to make sure it is in the right spot.

Select the CV’s shown here:

NOTE: To insert symmetrical isoparms in a closed surface requires that the seam be located along the plane of symmetry. You can use the ShowEdges command to visually highlight the seam to make sure it is in the right spot.

Select the CV’s shown here:

In the Front viewport, use the command ’Scale1D’ and stretch the CV's from the center of the head and outwards until the eyes no longer can be seen.

The surface that was stretched out needs a bit more tweaking. In the Top viewport, stretch the CV’s so the middle pair of CV’s are the most stretched.

Select the CV’s shown here:

Move these points up a bit to get a more rounded shape from the side view as well.

Select the CV’s shown below, and stretch them but inwards this time. With ’DynamicShadingPerspective’ you can see how much you need to stretch until the eyes become visible.

The areas just below the eyes needs more detail to look more convincing. Insert 3 isoparms:

Select the CV’s as shown below and move them down, so the isoparms follow the lower part of the eyes.

Select the middle of these 3 CV’s, and the ones next to it on each side:

Stretch these outwards, about half the way the upper eyebrows reach. Then tweak with each pair (one on each side) of these CV’s to get a smooth and decent look. If there is some area that seems hard to get smoother, choose the affected CV’s and with the ’Smooth’ command (smooth factor 0.1 recommended), smooth that area out. (Reference file ’brachio5.3dm).