Intro to Rhino T Splines

1. Rhino
The City University of New York
Architectural Technology Dept.
written by Severino Alfonso
Introduction to Rhino T-Splines

2. Rhino T-Splines
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Rhino T-Splines
Introduction
T-Splines: A modeling surface for design
T-Splines are a computer-aided design (CAD) surface.
Add detail only where necessary
T-Splines surfaces can contain areas with differing
levels of detail. Control points may be added only
where needed. A typical T-Splines surface will have up
to 50% fewer control points than the identical equiva-
lent set of NURBS surfaces.
T-Splines are similar to NURBS, with the difference
that you can have partial isoparms.
Create non-rectangular topology
Extrusions, holes, and other unique features are easy
to create in a T-Spline surface. This is a second differ-
ence between T-Splines and NURBS. NURBS require
multiple surfaces, or a polysurface, for such objects.
T-Splines can accomodate these features in a single
surface, through using a special point called a star
point.
T-Splines are like subdivision surfaces in this respect,
with the difference that you can insert geometry with-
out changing the surface.

3. Rhino T-Splines
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Rhino T-Splines
Starting with T-Splines
Edit Mode
Edit mode will show a gizmo based manipulator tool.
It allows for translations, rotations or scaling of the
entire model globally or one of the components of the
model individually or in groups (control points, edges
and faces).
1. Press Edit Mode On
2. Check that T-Spline Symbol is Active
3. Now you can work with manipulator

4. Rhino T-Splines
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Rhino T-Splines
Starting with T-Splines
Edit Mode On & Move
1. Press Edit Mode On
2. Check that T-Spline Symbol is Active
3. Press the move toggle button
4. Move gizmo appears in center of model
5. Now you can select axis or circle symbol near gizmo
to move model accordingly.
1.
2.
3.
4.

5. Rhino T-Splines
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Rhino T-Splines
Starting with T-Splines
Manipulator Options
Move
Rotate
Scale

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Rhino T-Splines
Starting with T-Splines
T-Spline Component Selection
Control Points
Edges
Faces

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Rhino T-Splines
Starting with T-Splines
T-Spline Component Selection & Manipulator Options
Make sure that Edit Mode is activated
Control Points On
Move
Rotate
Scale

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Rhino T-Splines
Starting with T-Splines
T-Spline Component Selection & Manipulator Options
Make sure that Edit Mode is activated
Edges On
Move
Rotate
Scale

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Rhino T-Splines
Starting with T-Splines
T-Spline Component Selection & Manipulator Options
Make sure that Edit Mode is activated
Faces On
Move
Rotate
Scale

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Rhino T-Splines
Starting with T-Splines
Primitives T-Spline Solids
Box
Variation in number of faces in the x,y,z direction

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Rhino T-Splines
Starting with T-Splines
Star Points
Create non-rectangular topology
Extrusions, holes, and other unique features are easy
to create in a T-Spline surface. This is a second differ-
ence between T-Splines and NURBS. NURBS require
multiple surfaces, or a polysurface, for such objects.
T-Splines can accomodate these features in a single
surface, through using a special point called a star
point.
To show Star Points in model:
1. Press on the Edit Layout Button
2. Press on the model
3. Model will show not smooth for Star Point display
4. Star Points (and T-points) will appear if there are
any inthe model
1.
2. 3.
4.

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Rhino T-Splines
Starting with T-Splines
T-Spline Primitives Examples
Box
Sphere
Torus
Quadball

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Rhino T-Splines
Starting with T-Splines
Box transformation 1
1. Select Box
2. Press Control Points On
3. Select Control Point
4. Delete Control Point
5. Model changes accordingly+ delete
control point

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Rhino T-Splines
Starting with T-Splines
Box transformation 2
1. Select Box
2. Press Edges On
3. Select Edge
4. Select Move button
5. Select vertical gizmo axis
6. Drag vertically and down to move line

15. Rhino T-Splines
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Rhino T-Splines
Starting with T-Splines
Box transformation 3
1. Select Box
2. Press Faces On
3. Select Faces
4. Select Scale button
5. Select center of scale gizmo
6. Drag horizontally to scale face

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Rhino T-Splines
Starting with T-Splines
Box transformation 4
1. Select Box
2. Press Faces On
3. Select 2 Faces (press shift to add to selection)
4. Select Rotate button
5. Select rotation curve from gizmo
6. Drag following curve to rotate faces

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Rhino T-Splines
Starting with T-Splines
Box transformation 5

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Rhino T-Splines
Starting with T-Splines
Box transformation 6
+ delete faces

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+ delete faces
Rhino T-Splines
Starting with T-Splines
Box transformation 7

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Rhino T-Splines
Starting with T-Splines
Insert edge between two edges
1. Press Insert Edge (simple)
2. Select first edge
3. Select second edge
4. Insert Edge between pair of selected edges
A main difference between T-Splines and NURBS is
the existence of T-points. A T-point is a vertex where
on one side, there is an isoparm, and on the other
side, there isn’t. This allows lines of detail to end el-
egantly. The surface is always smooth at a T-point.
NURBS don’t allow T-points.