[SOLVED] Where is P_CONTACTS declared?

Hello everyone!

I was trying to set up a simple character controller and I needed to check wether if a given rigidbody was grounded or not. I’m using this code snippet (got it from one of the examples)

MemoryBuffer contacts(eventData[P_CONTACTS].GetBuffer());
while (!contacts.IsEof()) {

     Vector3 contactPosition = contacts.ReadVector3();
     Vector3 contactNormal = contacts.ReadVector3();
     float contactDistance = contacts.ReadFloat();
     float contactImpulse = contacts.ReadFloat();
     // If contact is below node center and mostly vertical, assume it's a ground contact
     if (contactPosition.y_ < (node_->GetPosition().y_ + 1.0f)) {
         float level = Abs(contactNormal.y_);
         if (level > 0.75)
             onGround = true;

} [/code]

The compiler, though, keeps complaining about P_CONTACTS not being declared even though I’m including the same headers as the example (I know I don’t need many of those but I just tried to make sure before asking):

#include <iostream> #include "MemoryBuffer.h" #include "Context.h" #include "PhysicsEvents.h" #include "PhysicsWorld.h" #include "Scene.h" #include "SceneEvents.h" #include "PhysicsEvents.h"

A grep through the source reveals that this P_CONTACTS constant is being used in PhysicsWorld.cpp and PhysicsEvents.h, but I couldn’t find any declaration in either of them.

How can I solve this? Where is this variable declared and why does the example work but not my code?

How can I solve this

mb you must use Urho3D namespace

it is declared in Source/Engine/Physics/PhysicsEvents.h

/// Physics collision ongoing (sent to the participating scene nodes.)
PARAM(P_BODY, Body); // RigidBody pointer
PARAM(P_OTHERNODE, OtherNode); // Node pointer
PARAM(P_OTHERBODY, OtherBody); // RigidBody pointer
PARAM(P_TRIGGER, Trigger); // bool
PARAM(P_CONTACTS, Contacts); // Buffer containing position (Vector3), normal (Vector3), distance (float), impulse (float) for each contact

and you can use it to get the contacts as shown in the example 18_CharacterDemo.
here is the relevant code sample:

// Check collision contacts and see if character is standing on ground (look for a contact that has near vertical normal) using namespace NodeCollision; MemoryBuffer contacts(eventData[P_CONTACTS].GetBuffer());

did you forget to use the appropriat namespace ?
in this instance you have to use: “using namespace NodeCollision;”

if you dont know which namespace to use look which event you listen to and the second parameter in the event definition is the namespace:

and also you have to use the Urho3d namespace, just like in the example …

Thank you! I was missing the namespace, I was using Urho3D but not NodeCollision. Extra thanks for the tip on how to look for the Event’s namespace.