import iges file error with "M" unit - Forum Open Cascade Technology

Xia Zhengyuan
Mon, 05/13/2019 - 17:14

Forums:

Data Exchange and Application Framework

I import a iges file with "mm" unit, it seems ok. But error when I import the same iges file with "M" unit.

I think that maybe some parts not be converted from "MM" to "M".

I used the below code to use "M" unit for importing.

Interface_Static::SetCVal("xstep.cascade.unit", "M");

Attachments:

M.png

mm.png

AAC-1937_T26.zip

Kirill Gavrilov
Mon, 05/13/2019 - 17:52

I don't see anything similar in Draw Harnes or in CAD Assistant.
Which version of OCCT you are using?
How do you actually read IGES model? Any extra parameters changes?
How do you display the model in 3D Viewer?

pload ALL
param xstep.cascade.unit M
testreadiges {AAC-1937 (T26).igs} i
vclear
vinit View1
vdisplay -dispMode 1 i
vfit

Xia Zhengyuan
Tue, 05/14/2019 - 12:51

Dear Kirill, thanks for your replying very much. I used the code from the Freecad for testing, please see the attachment.

I use the version 7.3.0 of OCCT. I dumped the location and box for every shape into data_m.txt and data_mm.txt.

It seems that displaying for the "M" unit is right.

Attachments:

test_1.cpp

data_m.txt

data_mm.txt

Kirill Gavrilov
Tue, 05/14/2019 - 15:43

It seems that I'm not familiar with XDE enough to understand document exploration code of yours.

By the way, I believe you misunderstand what HashCode function does in OCCT - it does NOT guarantee lack of collisions, even if you give it INT_MAX as an upper limit.

std::set<int> myRefShapes;
static const int HashUpper = INT_MAX;
hash = aShape.HashCode(HashUpper);
if (isRef || myRefShapes.find(hash) == myRefShapes.end()) {

Xia Zhengyuan
Tue, 05/14/2019 - 20:31

Thank you, now I can read the model correctly. thanks.