Book Image

OpenFrameworks Essentials

Book Image

OpenFrameworks Essentials

Overview of this book

Table of Contents (19 chapters)
openFrameworks Essentials
About the Authors
About the Reviewers

Deforming a sphere

Deformation, that is, changing the geometry of a surface, gives an opportunity to create new and unusual 3D shapes. We will explore two methods of deformation: shifting the sphere's vertices using analytical formulas and extruding the sphere's surface using a texture's pixels values.

To implement this, let's start with adding several sliders to control deformation in the following way:

  1. Declare new sliders in the ofApp class:

    ofxFloatSlider rad, deform, deformFreq, extrude;

    This line declares four sliders: sphere radius, amount and frequency of analytical deformation, and amount of extrusion.

  2. Add commands to set up sliders to setup() after the mixerGroup.add( show3d.setup... command:

    mixerGroup.add( rad.setup("rad", 250, 0, 500) );
    mixerGroup.add( deform.setup("deform", 0.3, 0, 1.5) );
    mixerGroup.add( deformFreq.setup("deformFreq", 3, 0, 10) );
    mixerGroup.add( extrude.setup("extrude", 1, 0, 1 ) );

Deforming by formulas

We will implement the sphere deformation by changing positions...