View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0033726 | Community | OCCT:Mesh | public | 2024-05-23 13:46 | 2024-06-10 13:15 |
| Reporter | Dikran | Assigned To | oan | ||
| Priority | normal | Severity | minor | ||
| Status | new | Resolution | open | ||
| Platform | Windows | OS | VC++ 2017 | ||
| Product Version | 7.8.0 | ||||
| Summary | 0033726: Mesh - Failure to adequately render meshes containing B-Spline surfaces | ||||
| Description | The meshes generated for parts containing B-Splines present significant visual artefacts. The meshes are not visually acceptable to our clients. In the image provided, you will see that not enough points are added to reflect the part's shape. This is especially prevalent in high-curvature regions. In my assessment, this issue is caused by how nodes are appended to the mesh in the function GenerateSurfaceNodes within BRepMesh_NURBSRangeSplitter.cxx. I hope you can fix this issue soon. I remain at your disposal. Thanks in advance. Dikran | ||||
| Tags | No tags attached. | ||||
| Test case number | |||||
|
|
Coil-free_lin-def_0.8_ang-def_0.4.obj.png (304,842 bytes) Coil-free.step (88,354 bytes) |
|
|
Dear @Dikran, I am unable to reproduce the reported problem using current master (see attached screenshot). The following tcl script was used to simulate the use case: pload ALL stepread coil-free.step a * donly a_1 vinit vdefaults -autoTriang 0 vsetdispmode 1 # 0.4 rad is ~ 22.9 deg incmesh a_1 0.8 -a 23 vdisplay a_1 trinfo a_1 #This shape contains 4 faces. # 8034 triangles. # 4215 nodes. # 12 polygons on triangulation. Triangles number is very fine. Mesh on your screenshots obviously contains less triangles. Are you sure that the parameters are correct and the result is not influenced by some other functionality of your application? image.png (66,346 bytes) |
|
|
Dear @oan, thanks for the response! I have conducted further testing and obtained a similarly-looking render to yours by setting EnableControlSurfaceDeflectionAllSurfaces = true and ControlSurfaceDeflection = true. These changes have resulted in a visually acceptable part. However, the mesh associated with the part is highly irregular, with no apparent pattern in the nodes added. We require as regular a mesh as possible to conduct our post-processing tasks, so this mesh is still unacceptable. Moreover, enabling these parameter options has resulted in file sizes roughly 200 times larger in most parts tested (from 4MB to 980MB). File size is another limiting factor in our operation, so these substantial increases are problematic. Did you use EnableControlSurfaceDeflectionAllSurfaces = true and ControlSurfaceDeflection = true to generate the mesh you have attached? And if so, what does the output mesh look like? Lastly, is there a parameter that might improve the visual render without compromising the mesh quality? Thanks again for your assistance. I look forward to hearing from you. Kind regards, Dikran Coil-free_mesh_lin-def=0.8_ang-def=0.4.png (631,203 bytes) |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2024-05-23 13:46 | Dikran | New Issue | |
| 2024-05-23 13:46 | Dikran | Assigned To | => oan |
| 2024-05-23 13:46 | Dikran | File Added: Coil-free_lin-def_0.8_ang-def_0.4.obj.png | |
| 2024-05-23 13:46 | Dikran | File Added: Coil-free.step | |
| 2024-05-23 14:43 | dpasukhi | Summary | Failure to adequately render meshes containing B-Spline surfaces => Mesh - Failure to adequately render meshes containing B-Spline surfaces |
| 2024-05-23 14:43 | dpasukhi | Steps to Reproduce Updated | |
| 2024-05-24 13:13 | oan | Note Added: 0115898 | |
| 2024-05-24 13:13 | oan | File Added: image.png | |
| 2024-05-24 13:17 | oan | Note Edited: 0115898 | |
| 2024-05-24 13:46 | oan | Note Edited: 0115898 | |
| 2024-06-10 13:15 | Dikran | Note Added: 0116009 | |
| 2024-06-10 13:15 | Dikran | File Added: Coil-free_mesh_lin-def=0.8_ang-def=0.4.png |
