GG.scene().backgroundColor(@(0,0,0));
GG.camera().position(@(0,8,0));
GG.camera().lookAt( @(0,0,0) );

GSphere s1 --> GG.scene();
GSphere s5 --> GSphere s4 --> GSphere s3 --> GSphere s2 --> s1;
GPoints points --> GG.scene();

s1.mat().color(@(.030,.57,.55));

// s4.scale(@(.5,.5,.5));
// s3.scale(@(.6,.6,.6));
// s2.scale(@(.8,.8,.8));
// s1.scale(@(1,1,1));

s1.position(@(0,0,0));

points.posX(2);

// points stress test
50 => int POINTS_PER_AXIS;

// prepare vertex data for 1,000,000 points!
POINTS_PER_AXIS * POINTS_PER_AXIS * POINTS_PER_AXIS => int numPoints;
float pointPos[numPoints * 3];
float pointColor[numPoints * 4];

// populate within a 10x10x10 cube
for (int i; i < POINTS_PER_AXIS; i++) {
    for (int j; j < POINTS_PER_AXIS; j++) {
        for (int k; k < POINTS_PER_AXIS; k++) {
            // get the index of this vertex
            i * POINTS_PER_AXIS * POINTS_PER_AXIS + j * POINTS_PER_AXIS + k => int index;
            
            1.0 * POINTS_PER_AXIS => float colorScale;
            POINTS_PER_AXIS / 3.0 => float posScale;
            // caculate position
            i / colorScale => float x;
            j / colorScale => float y;
            k / colorScale => float z;
            
            // set position of this vertex
            (posScale * x) - (posScale / 2.0) => pointPos[3*index + 0];
            (posScale * y) - (posScale / 2.0) => pointPos[3*index + 1];
            (posScale * z) - (posScale / 2.0) => pointPos[3*index + 2];
            
            // set color of this vertex
            // (same as position, so have 1:1 mapping between xyz physical space and rgb color space) 
            x => pointColor[4*index + 0];
            y => pointColor[4*index + 1];
            z => pointColor[4*index + 2];
            .5 => pointColor[4*index + 3];  // alpha always 1
        }
    }
}

points.geo().positions(pointPos);  // set vertex position data
points.geo().colors(pointColor);   // set vertex color data

while (true) {
    // <<< GG.help() >>>;
    // GG.camera().rotY(GG.dt());
    GG.camera().posX(8*Math.sin(now/second*.5));
    GG.camera().posY(8*Math.cos(now/second*.5));
    GG.camera().lookAt( @(0,0,0) );
    GG.nextFrame() => now;
}