     // plasma sphere
 
     // return vec2(sdPlasmaSphere(p, 0.5), hue);
-    vec2(length(p)-.5 + plasma * sin(a / 10.), 100. * sin(plasma) + a),
+    vec2(length(p)-.5 + plasma * sin(a / 1e1), 1e2 * sin(plasma) + a),
     // plane
     vec2(1. + p.y, .0)
   );


  // castRay(ro, rd)
  float tmin = 1., mat = -1.;
  for( float i=.0; i<100.; i++ ) { // 64 = maxIterations
    cw = ro+rd*tmin;
    vec2 rayRes = map(cw);
    //float precis = .000001*tmin;

vec2 map(vec3 p) {
  float plasma = sin(5. *
    // horizontal sinusoid
    sin(1e1 * p.x + a * 2.) +
    // rotating sinusoid
    sin(1e1 * (p.x * sin(a / 2.) + p.z * cos(a / 3.)) + a) +
    // circular sinusoid
    sin(sqrt(1e1 * (
      // cx
      pow(p.x * sin(a / 2.), 2.) +
      // cy
