} else {    // hither clipping yields one triangle
          t = (near - v0.w)/(v2.w - v0.w);
          Vertex3D.lerp(v2, v0, v2, t);
          rgb[2] = rgbLerp(rgb[0], rgb[2], t);
          t = (near - v0.w)/(v1.w - v0.w);
          Vertex3D.lerp(v1, v0, v1, t);
          rgb[1] = rgbLerp(rgb[0], rgb[1], t);
          v0 = normalize(v0);
          v1 = normalize(v1);
          v2 = normalize(v2);
          ClipYon(raster);
        }
      }
    }