Triangulate Polygon object

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 02/01/2009 at 05:40, xxxxxxxx wrote:

User Information:
Cinema 4D Version:   10.1
Platform:   Windows ; Mac ;
Language(s) :     C++ ;

---------
Hi,

since I got the same problem as fused (see this thread), I tried to get a correctly triangulated model like this:

> \> void TriangulatePolygonObject(PolygonObject \*op, BaseDocument \*doc, PolygonObject \*res) \> { \> PolygonObject \*cObj = (PolygonObject\* )(op->GetClone(COPY_NO_BRANCHES|COPY_NO_BITS|COPY_NO_INTERNALS, NULL)); \> cObj->SetMg(op->GetMg()); \> \> ModelingCommandData cd; \> cd.doc = doc; \> cd.op = cObj; \> if (SendModelingCommand(MCOMMAND_TRIANGULATE, cd)) \> { \> PolygonObject \*result = (PolygonObject\* )(cd.result->GetIndex(0)); \> if(result) \> { \> result->CopyTo(res, COPY_NO_BRANCHES|COPY_NO_BITS|COPY_NO_INTERNALS, NULL); \> PolygonObject::Free(result); \> } \> } \> PolygonObject::Free(cObj); \> }

But it doesn't work. SendModelingCommand() always returns TRUE, indicating the command was executed. But result is always NULL. Where's the problem? I call the function like this:

> PolygonObject \*OrgObj = ToPoly(op); \> PolygonObject \*TriObj = PolygonObject::Alloc(OrgObj- >GetPointCount(), OrgObj->GetPolygonCount()); \> TriangulatePolygonObject(OrgObj, doc, TriObj); \>

Op is a plane, a landscape or any converted polygon object. Always the same NULL result.

Tahnks for any help!

Cheers,
Jack

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 02/01/2009 at 08:30, xxxxxxxx wrote:

i believe the object you specify in ModelingCommandData is modified and result is supposed to be NULL.

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 02/01/2009 at 10:06, xxxxxxxx wrote:

I don't understand. Modified? You mean it's different from the original object in the document?

Well, I tried to create a temporary document and insert the polygon object there before calling the modeling command (some example by Matthias showed how to do that). But it didn't change the result at all.

I really have no idea... Also, I still wonder why the Triangulate() function simply outputs a load of crap.

Cheers,
Jack

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 02/01/2009 at 11:22, xxxxxxxx wrote:

The triangulation occurs directly on the original object.

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 02/01/2009 at 12:03, xxxxxxxx wrote:

Ah, OK, that wasn't clear to me. Thanks Robert :)

But it is still not working as expected.
As I understood it, the following code should work:

> Bool TriangulatePolygonObject(PolygonObject \*op, BaseDocument \*doc, PolygonObject \*res) \> { \> res = (PolygonObject\* )(op->GetClone(COPY_NO_ANIMATION|COPY_NO_BITS|COPY_NO_INTERNALS, NULL)); \> res->SetMg(op->GetMg()); \> \> ModelingCommandData cd; \> cd.doc = doc; \> cd.op = res; \> return SendModelingCommand(MCOMMAND_TRIANGULATE, cd); \> }

But if e.g. op is a polygon object containing one quad polygon, performing - >GetPolygonCount() on resulting object res still only returns 1. Even better: If I get the points coordinates of this one polygon, they are all 0.

Damn, how hard can it be to triangulate a simple object?

Cheers,
Jack

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 02/01/2009 at 12:21, xxxxxxxx wrote:

Addition: It seems that the object actually IS correctly triangulated. When I add the following line before returning the result...

> GePrint("Poly count: " + LongToString(res->GetPolygonCount()));

...it outputs "Poly count: 2" in the console.

But when I call the function and try to get the poly count in the main function...

> PolygonObject \*OrgObj = ToPoly(op); \> \> PolygonObject \*TriObj = PolygonObject::Alloc(OrgObj->GetPointCount(), OrgObj->GetPolygonCount()); \> \> TriangulatePolygonObject(OrgObj, doc, TriObj); \> \> GePrint("Poly count: " + LongToString(TriObj->GetPolygonCount()));

...it outputs "Poly count: 1" again. If I declare TriObj as NULL, it is still NULL after calling TriangulatePolygonObject(), but inside TriangulatePolygonObject() the pointer res is not NULL, since it's getting a clone of the original object.

I really don't understand. Sorry. I bet it's something totally stupid. It seems that everything I do to res just works inside TriangulatePolygonObject(), but the result is not stored in the original object whose pointer was passed to the function.

Greetings,
Jack

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 02/01/2009 at 13:18, xxxxxxxx wrote:

Just for the archives: Solved the problem. But I have no idea why it didn't work like I showed in the 2 postings above.

Solution is here.

> Bool TriangulatePolygonObject(PolygonObject \*op, BaseDocument \*doc)//, PolygonObject \*res) \> { \> ModelingCommandData cd; \> cd.doc = doc; \> cd.op = op; \> Bool result = SendModelingCommand(MCOMMAND_TRIANGULATE, cd); \> return result; \> } \>

Cloning the original object has to be done *before* the function is called. I now do it like this:

> PolygonObject \*OrgObj = ToPoly(op); \> PolygonObject \*TriObj = (PolygonObject\* )(OrgObj->GetClone(COPY_NO_ANIMATION|COPY_NO_BITS|COPY_NO_INTERNALS, NULL)); \> if (!TriangulatePolygonObject(TriObj, doc)) return FALSE; \>

Now TriObj contains the triangulated geometry. Don't forget to free it after use ;-)

Greetings,
Jack

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 06/01/2009 at 03:26, xxxxxxxx wrote:

Ah, so solved your problem on your own. Glad it worked out.

cheers,
Matthias

Helper

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 06/01/2009 at 05:18, xxxxxxxx wrote:

Yeah, but I solved by pure chance.
Still don't understand the reason ;-)

Greetings,
Jack