Hello,
On 08/06/2014 02:33 PM, Sonya Blade wrote:
> Thank you for the entrypoint,
>
> What you mean by rescaling the geomtry directly? Directly modify the vertices
> and dirty the displaylist, rather than using
> transformation matrices? I'll try that workaround, it sounds quite coherent
> for the reason of discrepancy.
Yes, I meant modifying the vertex coordinates.
>> I can see that you are using
>> setIntersectionLimit(osgUtil::Intersector::LIMIT_ONE_PER_DRAWABLE )
>> which should be doing what I meant by "only-first-intersection".
> I personally not observed any improvement in Polytope behaviour in any of the
> (/NO_LIMIT, //LIMIT_ONE_PER_DRAWABLE/
> , /LIMIT_NEAREST/ etcc.. settings, in any case it retrieves plenty of
> objects.
I found the the reason why your code produces to many intersection:
You must call setIntersectionLimit(osgUtil::Intersector::LIMIT_ONE_PER_DRAWABLE
)
before the result collection starts, i.e.:
polytop->setIntersectionLimit(osgUtil::Intersector::LIMIT_ONE_PER_DRAWABLE );
osgUtil::IntersectionVisitor iv(polytop);
view->getCamera()->accept(iv);
Then I do get at most 5 intersecions with your example as is to be expected.
> Regards,
Cheers,
Peter
>> Date: Wed, 6 Aug 2014 14:16:31 +0200
>> From: [email protected]
>> To: [email protected]
>> Subject: Re: [osg-users] Erratical behaviour with PolytopeIntersector
>>
>> Hello again,
>>
>> On 08/06/2014 10:28 AM, Sonya Blade wrote:
>> > Hi All and Thanks for your feedback,
>> >
>> > Please find the reproduced example and obj file at the attachment, it
>> > doesn't have any visual aids,
>> > with 1st user click program creates leftbottom of rectangle, second user
>> > click creates righttop,
>> > for intersection rectangle and invokes PolytopeIntersector. If I select
>> > them all I'd expect totally 5
>> > objects to be picked, but program produces 420. There is a high chance
>> > that as Sebastian Messerschmidt
>> > emphasized, I pick all vertices but can you confirm it ?
>>
>> Thanks for your example.
>>
>> I can see that you are using
>> setIntersectionLimit(osgUtil::Intersector::LIMIT_ONE_PER_DRAWABLE )
>> which should be doing what I meant by "only-first-intersection".
>>
>> Testing your example I do get a lot more intersecions than is to be expected.
>> Clearly something is wrong there.
>>
>> But I think I found the reason for the "erratic" part of your problem:
>> Currently PolytopeIntersector does not produce correct results in presence
>> of scaling transformations (which are used in your example).
>>
>> As a workaround you could rescale your geometry directly.
>>
>>
>> Cheers,
>>
>> Peter
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