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IDProjectCategoryView StatusLast Update
0033601CommunityOCCT:Data Exchangepublic2024-02-15 16:25
ReporterPeterB Assigned Toika  
PrioritynormalSeverityjust a question 
Status newResolutionopen 
PlatformWindowsOSVC++ 2019 
Product Version7.7.1 
Summary0033601: Level of Detail (LOD) filtering support during STEP imports
we wonder whether OpenCascade features LOD (level of detail) filtering during STEP imports.

We generate six 2D views from STEP files.

For some STEP files this processing takes very long - esp. these phases / function calls:
+ Handle_HLRBRep_Algo::Update()
+ Handle_HLRBRep_Algo::Hide()

And it results in a huge number of graphic items.

That's why we would like to use LOD filtering to reduce both processing time and number of graph items in such cases.

Attached you'll find our STEP-to-DXF Windows cmdline tool, that showcases how we use OpenCascade to generate these six 2D views.
You might know this tool already from some of our OCC issue tracker tickets.

Pls search for this function:
+ StepImportImpl::TransferTo2d()

Thanks in advance and looking forward to your response!

Best regards,
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2024-02-14 22:44

reporter (10,277 bytes)


2024-02-15 16:25

administrator   ~0115104

Dear @PeterB, the quastion is not clear.
LOD is out-of-context of your program. LOD used to determinate level of mesh to render. And we use that on 0-9 pre-defined levels for visualization only.
OpenSource HLR don't working with mesh directly, they working with geometry.
That is why we can't correcly answer your quastion.
Any result that you recieve from STEP is geometry. It is not possible to leveling geometry quility.

Best regards, Dmitrii.

Issue History

Date Modified Username Field Change
2024-02-14 22:44 PeterB New Issue
2024-02-14 22:44 PeterB Assigned To => ika
2024-02-14 22:44 PeterB File Added:
2024-02-15 16:25 dpasukhi Note Added: 0115104