missing faces in a collision tree

[KamiGazz]

Hi,
I am trying to build a collision tree from a mesh I have within my graphic engine.

My trouble is that some faces are missing. I implemented some function to draw the wireframe of the actual mesh and wireframe of the collision geometry and I can clearly see that some faces are missing.

Code: Select all

for (i=0; i < NbrFaces*3; i=i+3)
   {
      Mesh->GetTriangleInfo(i/3,&vec1, &vec2, &vec3, &Group);
      Mesh->GetVertex(vec1, &sVertex[i].x,   &sVertex[i].y,   &sVertex[i].z,   &Temp,&Temp,&Temp,&Temp,&Temp,&Temp,&Temp,&color);
      Mesh->GetVertex(vec2, &sVertex[i+1].x, &sVertex[i+1].y, &sVertex[i+1].z, &Temp,&Temp,&Temp,&Temp,&Temp,&Temp,&Temp,&color);
      Mesh->GetVertex(vec3, &sVertex[i+2].x, &sVertex[i+2].y, &sVertex[i+2].z, &Temp,&Temp,&Temp,&Temp,&Temp,&Temp,&Temp,&color);
      NewtonTreeCollisionAddFace(Collision, 3, &sVertex[i/3].x, sizeof(sVERTEX), 1);
   }


The code is quite simple and.... I use the same to draw lines between vertices... and this show a perfect wireframe... so why some faces are missing in the collision geometry??
Any idea or way I could debug this??

[KamiGazz]

I forgot, here is the code that draw the newton geometry wireframe.

Code: Select all

void DebugShowGeometryCollision (void* userData, int vertexCount, const dFloat* faceVertec, int id)
{
   CTVScreen2DImmediate* p2D = new CTVScreen2DImmediate();
int i = vertexCount - 1;
dVector p0 (faceVertec[i * 3 + 0], faceVertec[i * 3 + 1], faceVertec[i * 3 + 2]);
   for (int i = 0; i < vertexCount; i ++)
   {
      dVector p1 (faceVertec[i * 3 + 0], faceVertec[i * 3 + 1], faceVertec[i * 3 + 2]);
      p2D->Draw_Line3D(p0.m_x, p0.m_y, p0.m_z, p1.m_x, p1.m_y, p1.m_z, WHITE, -2);
      p0 = p1;
   }
}


void CL3DObject::NewtonDebug(void)
{
   dMatrix matrix;
   NewtonBodyGetMatrix(pbody, &matrix[0][0]);
   NewtonCollisionForEachPolygonDo (NewtonBodyGetCollision(pbody), &matrix[0][0], DebugShowGeometryCollision, NULL);
}


I'm pretty sure this code is ok because the physics interaction match the missing faces.... object goes through my mesh where some faces are missing in the wireframe.

[Julio Jerez]

is this core 300?

try not using the optimization flag

[KamiGazz]

no, this is version 2.53.

Maybe I should swtich to core 300... I guess I was simply too lazy to compile the library!


Changing the Optimization flag gives the same result, I already tested it before I posted my issue... :S

[Julio Jerez]

do you mean core 1.53? thsi is abpu 8 year old code? I do nor even have the sorce anymore.

if you change the optimization flag, and you got the same result, then ther must be a bug in the code the feed the face to the collision tree.
Not optimized collsion meshes are identical to the original meshes. are you sure your mesh is not a veryex list index list and you are reading the wrong points?

also I recomend moving to core 300, there are great improvement and new funtionlity that does no exist in core 200

[KamiGazz]

oups... I meant 2.36! I like old school style but not that much!

"are you sure your mesh is not a veryex list index list and you are reading the wrong points?"

I'm not sure I understand what you mean there... but as you can see in the code of my first post, I retreive the vertex faces by faces.

GetTriangleInfo is a built in fonction of my graphic engine that return the indices of the 3 vertices of a face. I then use this info to push the vertices infos in the NewtonTreeCollisionAddFace().

Plus, If I replace the NewtonTreeCollisionAddFace by my debug method that draw a line between the 3 vertex of the face, I get a perfect wireframe of my mesh....


I downloaded core 300 yesterday, I will test it as soon as I am able to compile the DLL, cuz for now I can compile static lib but I'm having linker error to compile the DLL.

[KamiGazz]

I'm sure you get bored of hearing this Julio but... you were right!

Code: Select all

for (i=0; i < NbrFaces*3; i=i+3)
   {
      Mesh->GetTriangleInfo(i/3,&vec1, &vec2, &vec3, &Group);
      Mesh->GetVertex(vec1, &sVertex[i].x,   &sVertex[i].y,   &sVertex[i].z,   &Temp,&Temp,&Temp,&Temp,&Temp,&Temp,&Temp,&color);
      Mesh->GetVertex(vec2, &sVertex[i+1].x, &sVertex[i+1].y, &sVertex[i+1].z, &Temp,&Temp,&Temp,&Temp,&Temp,&Temp,&Temp,&color);
      Mesh->GetVertex(vec3, &sVertex[i+2].x, &sVertex[i+2].y, &sVertex[i+2].z, &Temp,&Temp,&Temp,&Temp,&Temp,&Temp,&Temp,&color);
     
      NewtonTreeCollisionAddFace(Collision, 3, &sVertex[i/3].x, sizeof(sVERTEX), 1);    *****   THERE IS NO NEED FOR /3 HERE ****
   }

At least, positive thing is that this hole search kicked my ass to move on to core 300!
Thx