code: package org.sunflow.core.shader;
  
  import org.sunflow.SunflowAPI;
  import org.sunflow.core.ParameterList;
  import org.sunflow.core.Shader;
  import org.sunflow.core.ShadingState;
  import org.sunflow.image.Color;
  import org.sunflow.math.Vector3;
  
  public class NormalShader implements Shader {
      public boolean update(ParameterList pl, SunflowAPI api) {
          return true;
      }
  
      public Color getRadiance(ShadingState state) {
          Vector3 n = state.getNormal();
          if (n == null)
              return Color.BLACK;
          float r = (n.x + 1) * 0.5f;
          float g = (n.y + 1) * 0.5f;
          float b = (n.z + 1) * 0.5f;
          return new Color(r, g, b);
      }
  
      public void scatterPhoton(ShadingState state, Color power) {
      }
  }