message: Writing low bytes of elem ID to high bytes attachment.
diff: @@ -450,6 +450,7 @@ if (u_featureInfo.x <= kFeatureDimension_SingleUniform) {
  } else {
  vec2 texc = computeElementIdTextureCoords();
  v_element_id0 = TEXTURE(u_elementIdLUT, texc);
  + texc.x += g_elementId_stepX;
  v_element_id1 = TEXTURE(u_elementIdLUT, texc);
  }`;
  