Bezier Surface Example - Fixed for XDL

Changes Made

The original 05_complex_bezier.m file had several features that are not yet supported in XDL:

Original Issues

  1. Complex numbers (-1-1i, etc.) - Not supported
  2. Nested function definitions - Not supported
  3. MATLAB-specific functions - meshgrid, subplot, figure, surf, nchoosek not fully implemented
  4. 2D array literal syntax with $ continuation - Not supported
  5. Multi-dimensional array indexing - Limited support

Solution

Rewrote the script as 05_bezier_surface.xdl using XDL-compatible features:

  1. Replaced complex numbers with real-valued control points
  2. Removed nested functions - expanded Bernstein polynomial calculations inline
  3. Used 1D arrays instead of 2D with manual index calculation (idx = ui * steps + vi)
  4. Added reform() to reshape 1D array to 2D for surface plotting
  5. Simplified to single surface plot instead of multiple subplots

Result

A working Bezier surface generator that:

  • Computes cubic Bernstein basis functions
  • Creates a smooth parametric surface from 4x4 control points
  • Generates a 3D surface plot
  • Provides statistical analysis of the surface

Usage 

./target/release/xdl examples/matlab/05_bezier_surface.xdl

Or from the GUI:

./target/release/xdl-gui
# Then File -> Open -> examples/matlab/05_bezier_surface.xdl

Output

  • Console output with surface statistics
  • xdl_surface.png - 3D visualization of the Bezier surface

Technical Notes

The script demonstrates:

  • Parametric surface generation
  • Cubic Bernstein polynomial blending
  • Array manipulation and indexing in XDL
  • Surface plotting capabilities
  • Statistical analysis functions (mean, stddev, min, max)