Adding lights

In this chapter, we will learn how to illuminate a 3D scene using OpenGL lights.

Getting ready

Include the necessary files to use OpenGL lights, materials, and draw. Add the following code to the top of the source file:

#include "cinder/gl/gl.h"
#include "cinder/gl/Light.h"
#include "cinder/gl/Material.h"

Also add the following using statements:

using namespace ci;
using namespace ci::app;
using namespace std;

How to do it…

We will use the default OpenGL light rendering methods to illuminate our scene. We will use the ci::gl::Material and ci::gl::Light classes, which are wrappers around the OpenGL functionality.

1. Declare ci::gl::Material to define the material properties of the objects being drawn and ci::Vec3f to define the lights position.

   gl::Material mMaterial;
   Vec3f mLightPos;

2. Let's set the materials Ambient, Diffuse, Specular, Emission, and Shininess properties by adding the following code in the setup method:

   mMaterial.setAmbient( Color::black() );
   mMaterial.setDiffuse( Color( 1...