explode_rotate.vex

vector center = point(1, 'P', 0);
float scale = chf('scale');
float scale_expand_limit = 2;
float scale_expand = min((scale - 1) * 4, scale_expand_limit) * scale_expand_limit;
scale_expand = smooth(0, scale_expand_limit, scale_expand) * scale_expand_limit;

vector centroid = prim(0, "centroid", @primnum);
vector offset = centroid - center;
float noise_val = noise(centroid * 10);
vector offset_with_noise = offset * noise_val;

float off_len = length(offset) * scale_expand;
float initial_rot = atan2(offset.z, offset.x);

// Rotate around center
vector point_offset = @P - centroid;
float cent_init_rot = atan2(point_offset.z, point_offset.x);
float cent_off_len = length(point_offset);
@P.x = centroid.x + cent_off_len * cos(cent_init_rot + (scale - 1) * -2 * noise_val);
@P.z = centroid.z + cent_off_len * sin(cent_init_rot + (scale - 1) * -2 * noise_val);

@P.x += off_len * cos(initial_rot + (noise_val * scale))* (scale - 1);
@P.z += off_len * sin(initial_rot + (noise_val * scale)) * (scale - 1);
@P.y += offset_with_noise.y  * (scale - 1) * 2;

// Other attributes
vector color = rgbtohsv(rand(@piece));
color.y = 1;
color = hsvtorgb(color);
@Cd = color;
v@emitcolor = color;
v@transcolor = color;