diff --git a/src/libslic3r/PrintObject.cpp b/src/libslic3r/PrintObject.cpp index 5cebbb0566..419536bf4d 100644 --- a/src/libslic3r/PrintObject.cpp +++ b/src/libslic3r/PrintObject.cpp @@ -627,12 +627,21 @@ bool PrintObject::invalidate_state_by_config_options( || opt_key == "bottom_fill_pattern" || opt_key == "external_fill_link_max_length" || opt_key == "fill_angle" - || opt_key == "fill_pattern" || opt_key == "infill_anchor" || opt_key == "infill_anchor_max" || opt_key == "top_infill_extrusion_width" || opt_key == "first_layer_extrusion_width") { steps.emplace_back(posInfill); + } else if (opt_key == "fill_pattern") { + steps.emplace_back(posInfill); + + const auto *old_fill_pattern = old_config.option>(opt_key); + const auto *new_fill_pattern = new_config.option>(opt_key); + assert(old_infill && new_infill); + // We need to recalculate infill surfaces when infill_only_where_needed is enabled, and we are switching from + // the Lightning infill to another infill or vice versa. + if (m_config.infill_only_where_needed && (new_fill_pattern->value == ipLightning || old_fill_pattern->value == ipLightning)) + steps.emplace_back(posPrepareInfill); } else if (opt_key == "fill_density") { // One likely wants to reslice only when switching between zero infill to simulate boolean difference (subtracting volumes), // normal infill and 100% (solid) infill.