创建一个电磁场效果着色器，包含电场和磁场效果，支持场线显示，提供三种场类型可选。

uniform float uTime;
uniform float uElectricField;
uniform float uMagneticField;
uniform float uWaveFrequency;

void main() {
    vUv = uv;
    vPosition = position;
    vNormal = normal;

    float electricWave = sin(position.x * 8.0 + uTime * uElectricField * 2.0) *
                       cos(position.y * 6.0 + uTime * uElectricField * 1.5) *
                       sin(position.z * 4.0 + uTime * uElectricField * 0.8);

    float magneticRing = sin(distance(position, vec3(0.0)) * 10.0 + uTime * uMagneticField * 3.0) *
                       cos(uTime * uMagneticField * 2.0);

    float fieldLines = sin(position.x * 12.0 + uTime * uWaveFrequency * 4.0) *
                     cos(position.z * 12.0 + uTime * uWaveFrequency * 4.0);

    vec3 newPosition = position + normal * (electricWave * 0.2 + magneticRing * 0.15 + fieldLines * 0.1);

    gl_Position = projectionMatrix * modelViewMatrix * vec4(newPosition, 1.0);
}

vec3 electricField(vec2 uv, float intensity) {
    vec3 electricColor = vec3(0.2, 0.6, 1.0);
    float electricLines = 0.0;
    electricLines += sin(uv.x * 20.0 + uTime * 3.0) * 0.3;
    electricLines += sin(uv.y * 15.0 + uTime * 2.5) * 0.2;
    float electricWave = sin(uv.x * 8.0 + uTime * 2.0) *
                       cos(uv.y * 6.0 + uTime * 1.5);
    return electricColor * (electricLines + electricWave) * intensity;
}

vec3 magneticField(vec2 uv, float intensity) {
    vec3 magneticColor = vec3(1.0, 0.2, 0.6);
    vec2 center = vec2(0.5, 0.5);
    float dist = distance(uv, center);
    float magneticRing = sin(dist * 15.0 + uTime * 2.5) *
                       cos(uTime * 3.0);
    float magneticLines = 0.0;
    if(uShowFieldLines) {
      magneticLines += sin(atan(uv.y - 0.5, uv.x - 0.5) * 8.0 + uTime * 2.0) * 0.2;
    }
    return magneticColor * (magneticRing + magneticLines) * intensity;
}