Newton2 - Heightmap user ID fail?

[Aphex]

hey,

I've just moved over from a user collision to a heightmap collision (NewtonCreateHeightFieldCollision).
I set the heightmap collision user ID to a specific value on creation, but when I iterate over all bodies (NewtonWorldGetFirst/NextBody) and check their collision ID, I don't appear to ever get back the ID value I set..?

[ed] In fact, the user ID value I get back for the island looks more like a pointer (for instance 0x05d7e180 in my last run...)

[Julio Jerez]

can you post a code fragement?

[Aphex]

okeys:

Set up collision:

Code: Select all

   // New heightfield collision:
   char* attributes = new char[mHeightMap->Width()*mHeightMap->Height()];
   STATIC_CHECK(sizeof(unsigned short)==sizeof(THeightVal)); // fn below takes unsigned shorts for height vals.
   NewtonCollision* collision = NewtonCreateHeightFieldCollision(physWorld, mHeightMap->Width(), mHeightMap->Height(), 1, (unsigned short*)mHeightMap->DataPtr(), attributes, KIslandScale, mHeightScale);
   NewtonStaticCollisionSetDebugCallback(collision, HeightfieldCollisionDebugCallback);
   delete [] attributes;
   NewtonConvexCollisionSetUserID(collision, NPhysEng::KCollisionIdIsland);  <- KCollisionIdIsland = 37
   mPhysicsBody = NewtonCreateBody(physWorld, collision);
   NewtonReleaseCollision (physWorld, collision);
   NewtonBodySetUserData(mPhysicsBody, this);
   NewtonBodySetMaterialGroupID(mPhysicsBody, NMaterials::IdFromType(NMaterials::EEarth));
   const TMatrix4d orient(WorldPos()-TWorldPos(mHeightMap->Width()*0.5*KIslandScale-7, -mHeightOffset, mHeightMap->Height()*0.5*KIslandScale-7));   // origin at top left...
#endif
   NewtonBodySetMatrix(mPhysicsBody, orient.Ptr());


Get user id back:

Code: Select all

   NewtonBody* body = NULL;
   for (body=NewtonWorldGetFirstBody(mPhysicsWorld) ; body!=NULL ; body=NewtonWorldGetNextBody(mPhysicsWorld, body))
   {
      GFXAPI().SetColor3f(NewtonBodyGetFreezeState(body)==0 ? TColor::Red() : TColor(0.5f, 0.0f, 0.0f));
      TMatrix4d matrix;
      NewtonBodyGetMatrix(body, matrix.Ptr());
      NewtonCollision* collision = NewtonBodyGetCollision(body);
      const unsigned int userId = NewtonConvexCollisionGetUserID(collision);  // <-- Get back what looks like a ptr here!
      if (userId!=KCollisionIdIsland || (userId==KCollisionIdIsland && gPhysEngShowIslandCollision))
      {
         NewtonCollisionForEachPolygonDo(collision, matrix.Ptr(), DebugShowGeometryCollision, NULL);
      }
   }


[Julio Jerez]

Oh I see whu the does no work.
Th ereason is that teh user teh collision object has a userdat type,
The type is a pointer I have to do that fo 64 bit compibility, bacause in soem plaform teh sized of pointe and inter an dlon ios differen tehref ro I use a usnion to make aligment consistent.
This si the problem copmbe collision use teh user dat atyeop to store a collision ID because all of teh faces have uniform properies.
poligonal meshes collision use user ID as a proinet to point to teh array and array of using dat ato stre the ID for each face and a hold bunch of other data.
I guess I can add anoeth member to store teh user data for collision trees,

can you use this function:

NewtonCollisionInfoRecord info;
NewtonCollisionGetInfo (collision, &info);

Edit:
I was wondering how can I made a mistake liek that, but that is no a mistake if you look carefullt the function name tells you taht collision ID can only be set on convex collision.
I can leave the userdata as it is, and add a new data id, then change the interface for
NewtonConvexCollisionSetUserID to NewtonCollisionSetUserID

does that sound like a solution

[Julio Jerez]

Ok I made the fix id Fix, using this NewtonConvexCollisionSetUserID to NewtonCollisionSetUserID
are you using the win64 or double?

[Aphex]

Yeah I did wonder about the 'convex' bit in the name, but then saw it was used in the sdk demos.
I'm using the double version I've got a workaround in place though, so I can live with it for a bit

[ed] whoops it wasn't in a demo - I think I just kept it around from the user collision I was using previously

[Julio Jerez]

Liek I said, I made teh chane alread
can you hold until I public the next Beta?
I was ocupid with other personal life issues, but now I am spending time finishing one of the the two features.
I beleive it will come to the rescue of the preblem you are having know with the car and the terrain.

I am hopping to have ready this weekend.

[Aphex]

Excellent - I can hold out Hope your life issues aren't bad ones.