[ODE] Plane-Cylinder collision: not good in 0.7, worse in SVN :(

[Mauro G. Todeschini]

Bram Stolk wrote:
> For me, cyl vs plane is OK for both geomoffset and trf geoms.
> 
> Could you please do this test against svn-tree?
> 
> - Run test_boxtest and press 'y' a few times.
> 
> - Edit test_boxstack.cpp and change line 94 to:
> #define USE_GEOM_OFFSET 0
>   Rebuild, and re-run the test.
> 
> For me, both cases are OK.
> I just tested this with current svn, on linux, with double prec.
Ok, the test you suggested works correctly in both cases but... I think
that changing the #define doesn't make any difference for cylinders (ie.
trf geoms are never used for cylinders). It only makes difference for
composite objects (which don't contain any cylinder, only capsules).
Try putting a printf after line 455 and You'll see that you never pass
from that line with cylinders.

In my application I discovered that the problem with planes and
transformed cylinders seems to happen when I define my plane like this
(gravity is dWorldSetGravity (world,0,-9.8,0);):

dCreatePlane (space,0,1,0,-20);

but the problem seems to disappear if:

dCreatePlane (space,0,1,0,0);

I think that the negative value in the first definition has something to
do with the problem.

Bye and Thanks

> 
>  Bram
> 
> 
> 
> 
> On Fri, 2006-10-27 at 18:09 +0200, LR wrote:
>> Hi Mauro,
>>
>> I have similars problems with cylinder & transform geoms (it's with the
>> sphere/cylinder). To resolve it, i made a compile switch witch enable me to
>> compile with "transform geoms" or with "GeomOffsets".
>>
>> Using geoms offsets solves the cylinder problems (but why ????). 
>>
>> LR
>>
>>
>>  
>>
>> -----Message d'origine-----
>> De : ode-bounces at q12.org [mailto:ode-bounces at q12.org] De la part de Mauro G.
>> Todeschini
>> Envoyé : vendredi 27 octobre 2006 15:58
>> À : ode-list mailing_list
>> Objet : [ODE] Plane-Cylinder collision: not good in 0.7, worse in SVN :(
>>
>> Hi,
>> 	today I downloaded ODE trunk from SVN to test the latest patches for
>> collisions between cylinder and plane. In ODE 0.7 there is some problem
>> (explosion) when the cylinder falls with a circular face parallel to the
>> plane (ground).
>> In SVN the explosion happens everytime a cylinder hits a plane (not only on
>> its circular face).
>> In my tests cylinders are transformed with geomTransforms.
>> I read in the mailing-list that there has been some work on the issue
>> (cylinder-plane collision) at the beginning of september, but I fear that It
>> has not been tested the case of cylinders in geomTransform.
>> Has anyone verified the behaviour of cylinders in geomTransforms recently
>> (after the changes)?
>>
>> Thanks and Bye
>>
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>>
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