ShaderMaterial material rendering effect

Questions
1

I use the shadow material to render the model. It is found that the rendered model is not very clear and the light-and-dark level is not high, how should this be set

vertexShader:
varying vec4 vPosition;
varying lowp vec3 vColor;
varying float vTransparent;
varying float vVisible;
varying vec3 pixelNormal;
void main()	{
    vUv = uv;
    vPosition = modelViewMatrix * vec4( position, 1.0 );
    vColor = color;
    vTransparent = transparent;
    pixelNormal = normal;
    gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
}

fragmentShader:
varying vec4 vPosition;
varying lowp vec3 vColor;
varying float vTransparent;
varying vec3 pixelNormal;
void main(){
      float shade = (
         3.0 * pow ( abs ( pixelNormal.y ), 2.0 )
        + 2.0 * pow ( abs ( pixelNormal.z ), 2.0 )
       + 1.0 * pow ( abs ( pixelNormal.x ), 2.0 )
     )/3.0;
     gl_FragColor = vec4(vColor * shade, vTransparent);
}
2

shadow material? Or ShaderMaterial?

On a side note, pow ( abs ( pixelNormal.y ), 2.0 ) can be simplified to pixelNormal.y*pixelNormal.y.

Have you tried simply using the (maybe abs) normals directly? What you will see when squaring numbers in the range (-1, 1) is that they become smaller in magnitude. In this case you have amplified the R and G channels, but B will invariably be weaker than its unsquared starting point.

3

is shaderMaterial

4

image
image.png1100×665 161 KB

This is the effect, and the whole is vague.

5

I think it looks cool. What is the problem?