# Selection by ID as default? **URL:** \ **Category:** Feature Requests\ **Created:** [March 17, 2026, 6:41am UTC](https://prepomax.discourse.group/t/selection-by-id-as-default/3346 "2026-03-17T06:41:22Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Gunnar](https://avatars.discourse-cdn.com/v4/letter/g/ed655f/32.png) [@Gunnar](https://prepomax.discourse.group/u/Gunnar)\ **Post date:** [March 17, 2026, 6:41am UTC](https://prepomax.discourse.group/t/selection-by-id-as-default/3346/1 "2026-03-17T06:41:22Z")
I’ve noticed that when selecting multiple bodies for meshing, there’s a significant difference in processing time depending on whether “Selection by Location” or “Selection by ID” is used. Selection by ID is much faster, while “by Location” stops working altogether after a certain number of bodies and Prepomax needs to be terminated. Therefore, if there are no objections, I would suggest defining “Selection by ID” as the default selection methode in the basic settings. The example involves two compounds, each consisting of 21 solids ![aaaa](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/b/bf286bfb55bcfb1d7ad8f825cb16c436f29c93d4.gif) Tested with v2.5.1, I don’t know if this behavior is consistent with earlier versions. ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [March 17, 2026, 9:05am UTC](https://prepomax.discourse.group/t/selection-by-id-as-default/3346/2 "2026-03-17T09:05:15Z")
To clarify the difference between them: > Two selection methods are available - by location and by ID. The first one is based on the location of the user selection (point or area). Location data is saved for when there is a need to recreate the selection (remeshing, regenerating). If the selection is recreated the location data is used to create the selection again. The second one uses the location of the user selection to get the geometry IDs of the underlying geometry and saves only the IDs. When the selection needs to be recreated the geometry IDs are directly used again. In standard usage, like remeshing and regenerating, those two methods are equivalent. However, if the geometry changes before remeshing or regenerating (_Regenerate Using Other Files_ or _Swap Part Geometries_), the results of the selection may change. If the topology (numbering of vertices, edges, and faces) does not change and only the geometry (dimensions) changes, the ID-based selection will always select the same vertex, edge, face of part while the location-based method might fail to do so. The ID-based method can also be used to create reference points and coordinate systems. ---
**Author:** ![Matej](https://avatars.discourse-cdn.com/v4/letter/m/a698b9/32.png) [@Matej](https://prepomax.discourse.group/u/Matej)\ **Post date:** [March 17, 2026, 11:51am UTC](https://prepomax.discourse.group/t/selection-by-id-as-default/3346/3 "2026-03-17T11:51:06Z")
I would not like to change the default behaviour, but if the selection method is slow, I can look into speeding it up. ---
**Author:** ![Gunnar](https://avatars.discourse-cdn.com/v4/letter/g/ed655f/32.png) [@Gunnar](https://prepomax.discourse.group/u/Gunnar)\ **Post date:** [March 17, 2026, 6:50pm UTC](https://prepomax.discourse.group/t/selection-by-id-as-default/3346/4 "2026-03-17T18:50:58Z")
Thank you. If optimization is possible, the request would of course be unnecessary 🙂