public Feature setBufferPixels(double buffer) {
      defaultBufferPixels = buffer;
      return this;
    }
Sets the default number of pixels of detail to render outside the visible tile boundary when no zoom-specific
override is set in {@link #setBufferPixelOverrides(ZoomFunction)}.
planetiler-core/src/main/java/com/onthegomap/planetiler/FeatureCollector.java