Two families of cubic Hermite curves forming a parametric net are the basis of the bicubic Hermite surface. Learn more about Chapter 7: Bicubic Hermite. Parametric Bicubic Surfaces. ▫ The goal is to go from curves in space to curved surfaces in space. ▫ To do this, we will parameterize a surface. bicubic surfaces. We want to define We want to define smooth surfaces too. Parametric but also have the nice Hermite property of continuous tangent vector.
|Published (Last):||13 January 2011|
|PDF File Size:||7.94 Mb|
|ePub File Size:||2.50 Mb|
|Price:||Free* [*Free Regsitration Required]|
L11 Hermite Bicubic Surface Patch – Free Download PDF
Define 4 corner points in 3D space. Describe how you can determine the shortest distance between, say, San Francisco and Taipei. Do the results make sense to you?
A parametric surface patch with its boundary conditions The twist vector at a point on a surface measures the twist in the surface at the point.
The normal to a surface is another important analytical property. The Gaussian curvature at a point on the surface is defined as. The bicubic equation can be written as. Thus, the boundary matrix for the F-surface patch becomes.
Bilinear Surface A bilinear surface is derived by interpolating four data points, using linear equations in the parameters u and v so that the resulting surface has the four points at its corners, denoted P 00P 10P 01and P 11as shown in Figure 1. For a 2-D parametric curve represented in terms of its arc length s.
L11 Hermite Bicubic Surface Patch
A parametric surface patch with its boundary conditions. For a 2-D parametric curvenote thatandEquation 21 can be transformed into.
surfsce The twist vector at a point on a surface measures the twist in the surface at the point. Draw the shortest path on the sphere. Equation 4 also tells us that a bilinear surface is obtained by simply blending the effects of the corner points after they are weighted by the blending functions 1- u surfce vu 1- v1- u vuv. Equation 11 can be further expressed as.
The mean curvature is defined as. Check out the definition of a?
Finally, write down the surface equations of your F-surface patch and write a simple Matlab program to draw the F-surface. Thus, the boundary matrix for the F-surface patch becomes Figure 3. The Hermite bicubic surface can be written in terms of the 16 input vectors: Hermite Bicubic Surface Because the blending functions are linear, the bilinear surface tends to be flat.
Equation 17 is often called the first fundamental quadratic form of a surface and is written as.
In general, two distinct points on a surface can be connected by many different paths, of different lengths, on the surface. Geometric properties of surfaces 1. Because the blending functions are linear, the bilinear surface tends to be flat. The attributes to be stored would be only four corner points because the surface represented by Equation 4 can be reconstructed from these four corner points.
Check out the latitudes and longitudes of Taipei, Tokyo, the North Pole, and San Francisco, and mark approximately the positions of the 4 cities on the earth. germite
Construct a sphere to represent the earth. Construct the boundary condition matrix [B] in Equation A bilinear surface is derived by interpolating four data points, using linear equations in the parameters u and v so that the resulting surface has the four points at its corners, denoted P 00P 10P 01and P 11as shown in Figure 1. Write syrface the bilinear surface equation using Equation 4. We can verify that the four data points are at the corners of the bilinear surface by substituting the proper combination of 0 and 1 for u and v in Equation 4.
Estimate the tangent vectors using the 4 corner points. Substituting Equation 1 sufface 2 into Equation 3 gives the following equation of a bilinear surface: As shown in Figure 2, 16 boundary bjcubic are required to find the coefficients of the equation. Geodesics In general, two distinct points on a surface can be connected by many different paths, of different lengths, on the surface.