# Mesh issue with midside nodes on geometry **URL:** \ **Category:** General Questions\ **Created:** [May 22, 2024, 2:59pm UTC](https://prepomax.discourse.group/t/mesh-issue-with-midside-nodes-on-geometry/1760 "2024-05-22T14:59:03Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![andrea.starnini](https://avatars.discourse-cdn.com/v4/letter/a/46a35a/32.png) [@andrea.starnini](https://prepomax.discourse.group/u/andrea.starnini)\ **Post date:** [May 22, 2024, 2:59pm UTC](https://prepomax.discourse.group/t/mesh-issue-with-midside-nodes-on-geometry/1760/1 "2024-05-22T14:59:03Z")
Is not the first time that I encountered this problem on hole with “midside nodes on geometry” on ![2024-05-22_165316](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/0/01a6f9d445217b4212a6a3206c11720db67de49a.jpeg) ---
**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:** [May 22, 2024, 4:17pm UTC](https://prepomax.discourse.group/t/mesh-issue-with-midside-nodes-on-geometry/1760/2 "2024-05-22T16:17:11Z")
Does it happen right after meshing or in an analysis ? Can you share the file ? ---
**Author:** ![SergioP1975](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/sergiop1975/32/37_2.png) [@SergioP1975](https://prepomax.discourse.group/u/SergioP1975)\ **Post date:** [May 22, 2024, 5:06pm UTC](https://prepomax.discourse.group/t/mesh-issue-with-midside-nodes-on-geometry/1760/3 "2024-05-22T17:06:58Z")
I have seen this same behavieur in the past with Netgen. The solution is uncheck the midside nodes on geometry, change the mesh size, change the mesher to Gmsh, or add a local refinement in the hole. ---
**Author:** ![Matej](https://avatars.discourse-cdn.com/v4/letter/m/a698b9/32.png) [@Matej](https://prepomax.discourse.group/u/Matej)\ **Post date:** [May 22, 2024, 6:28pm UTC](https://prepomax.discourse.group/t/mesh-issue-with-midside-nodes-on-geometry/1760/4 "2024-05-22T18:28:51Z")
This is a confirmed Netgen problem. ---
**Author:** ![synt](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/synt/32/4658_2.png) [@synt](https://prepomax.discourse.group/u/synt)\ **Post date:** [May 22, 2024, 6:53pm UTC](https://prepomax.discourse.group/t/mesh-issue-with-midside-nodes-on-geometry/1760/5 "2024-05-22T18:53:56Z")
try split cylindrical surface by extra edges or switch to Gmsh mesher probably can solve the problem. ---
**Author:** ![andrea.starnini](https://avatars.discourse-cdn.com/v4/letter/a/46a35a/32.png) [@andrea.starnini](https://prepomax.discourse.group/u/andrea.starnini)\ **Post date:** [May 30, 2024, 4:03am UTC](https://prepomax.discourse.group/t/mesh-issue-with-midside-nodes-on-geometry/1760/6 "2024-05-30T04:03:57Z")
I encountered again the same problem with relative coarse mesh for preliminary studies. I tried to mesh the same component in Mecway with the same parameter and all is correct. ![immagine](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/c/c43ebb1ed9d7b01d6f63c4420e89cbd1bcd0ccb2.png) ![immagine](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/1/11e2387fc35d0032bf1ea338e401e71e93b06d45.jpeg) ---
**Author:** ![Matej](https://avatars.discourse-cdn.com/v4/letter/m/a698b9/32.png) [@Matej](https://prepomax.discourse.group/u/Matej)\ **Post date:** [May 30, 2024, 6:49am UTC](https://prepomax.discourse.group/t/mesh-issue-with-midside-nodes-on-geometry/1760/7 "2024-05-30T06:49:42Z")
I see there is an option to straighten bad elements in the Mecway. Can you try disabling it (I don’t use Mecway) and PrePoMax has no such feature. ---
**Author:** ![andrea.starnini](https://avatars.discourse-cdn.com/v4/letter/a/46a35a/32.png) [@andrea.starnini](https://prepomax.discourse.group/u/andrea.starnini)\ **Post date:** [May 30, 2024, 8:25am UTC](https://prepomax.discourse.group/t/mesh-issue-with-midside-nodes-on-geometry/1760/8 "2024-05-30T08:25:13Z")
I will try to disable this option I tried and I didn’t have distorted elements. I tried setting minimum elements size to 2 mm. On the last case some distorted elements were generated. Activating “straighten bad elements” all elements are acceptable. ![immagine](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/5/5ac77ff4000399745dcf92d235a0ac7f6a0f3836.png) ---
**Author:** ![Matej](https://avatars.discourse-cdn.com/v4/letter/m/a698b9/32.png) [@Matej](https://prepomax.discourse.group/u/Matej)\ **Post date:** [June 2, 2024, 5:25pm UTC](https://prepomax.discourse.group/t/mesh-issue-with-midside-nodes-on-geometry/1760/9 "2024-06-02T17:25:37Z")
So maybe a check for element quality is needed in PrePoMax; once it is implemented, it can be used to detect such elements and fix their mid-nodes back to midpoints. ---
**Author:** ![andrea.starnini](https://avatars.discourse-cdn.com/v4/letter/a/46a35a/32.png) [@andrea.starnini](https://prepomax.discourse.group/u/andrea.starnini)\ **Post date:** [June 3, 2024, 5:13am UTC](https://prepomax.discourse.group/t/mesh-issue-with-midside-nodes-on-geometry/1760/10 "2024-06-03T05:13:32Z")
Generally, during CAD exporting, I don’t select this option because I can select cylindrical surfaces more quickly ---
**Author:** ![synt](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/synt/32/4658_2.png) [@synt](https://prepomax.discourse.group/u/synt)\ **Post date:** [June 7, 2024, 11:23pm UTC](https://prepomax.discourse.group/t/mesh-issue-with-midside-nodes-on-geometry/1760/11 "2024-06-07T23:23:30Z")
PrePoMax has option to select face by angle criteria, it can be fast also.