Angelscript + C++. Nullptr exception

I created scene in the editor and try to load it. I have followed AngelScript file, that does not want to work.

First, I load the scene like this

[code] SharedPtr file = g_pApp->GetConstantResCache()->GetFile(levelResource);
m_pScene = new Scene(context_);
m_pScene->LoadXML(*level);

m_pCameraNode = m_pScene->CreateChild("MainCamera");
m_pCameraNode->CreateComponent<Camera>();

// Set an initial position for the camera scene node above the plane
m_pCameraNode->SetPosition(Vector3(0.0f, 2.0f, -10.0f));
SharedPtr<Viewport> viewport(new Viewport(context_, m_pScene, m_pCameraNode->GetComponent<Camera>()));
m_pRenderer->SetViewport(1, viewport);

[/code]

  1. Then I have followed action script, which attachedto the object. All work fine, until I pressed space, in order to create prefab and try to set initial impulse.

[code]class Cannon : ScriptObject
{
if (input.keyDown[KEY_SPACE] && shootDelay <= 0.0f)
{
shootDelay = 1.0f;
Shoot();
AnimationController@ animCtrl = node.GetComponent(“AnimationController”);
animCtrl.SetTime(“Models/Shoot.ani”, 0.0f);
animCtrl.PlayExclusive(“Models/Shoot.ani”, 0, false, 0.0f);
}
}

void Shoot()
{
    Vector3 position = node.GetChild("CannonballPlace", true).worldPosition;

    XMLFile@ xml = cache.GetResource("XMLFile", "Objects/Cannonball.xml");
    Node@ newNode = scene.InstantiateXML(xml, position, Quaternion());
    
    RigidBody@ body = newNode.GetComponent("RigidBody");
    body.ApplyImpulse(node.rotation * Vector3(0.0f, 1.0f, 0.0f) * 15.0f);
}

}[/code]

When I try to InstantiateXML, my program crashed and I have the following output.

ERROR: Scripts/Cannon.as:47,13 - Exception ‘Null pointer access’ in 'void Cannon::Update(float)'
AngelScript callstack:
Scripts/Cannon.as:void Cannon::Update(float):47,13

I have checked that all path are correct.

How I can fix it ?

[quote=“Sinoid”]Are you using 1.4 or HEAD from git?

Also, include the entire code from your Cannon.as file - or at least prefix the lines you do provide with their line numbers. Almost impossible to help with what you’ve given.[/quote]

I am not quite sure, but I think I use 1.4 version. I just clone repository from github.com/urho3d/Urho3D, and compiled it with vs2013. But, what is HEAD version ?

I uploaded Cannon.as file below. I get error, when press space, like this

[Sat Oct 03 09:51:27 2015] ERROR: Scripts/Cannon.as:19,9 - Exception ‘Null pointer access’ in ‘void Cannon::Shoot()’
AngelScript callstack:
Scripts/Cannon.as:void Cannon::Shoot():19,9
Scripts/Cannon.as:void Cannon::Update(float):7,4

Also I have checked, that if I comment Shoot function, animation works fine.

UPDATED.

I have written function Shoot() in C++. All works fine. So, there is problem with AngelScript, especially with InstantiateXML fucntion. :exclamation:

Vector3 pos = m_pScene->GetChild("CannonballPlace", true)->GetWorldPosition(); XMLFile* xml = g_pApp->GetConstantResCache()->GetResource<XMLFile>("Objects/Cannonball.xml"); Node* newNode = m_pScene->InstantiateXML(xml->GetRoot(), pos, Quaternion()); RigidBody* body = newNode->GetComponent<RigidBody>("RigidBody"); body->ApplyImpulse(m_pScene->GetChild("Cannon")->GetRotation() * Vector3(0.0f, 1.0f, 0.0f) * 15.0f);

I tried to write in script xml.root too, but it failed anyway.

That would be HEAD/master. Angelscript was recently updated in master, I just needed to know whether you were using Angelscript 2.29 or 2.30.2.

Everything appears to be fine with InstantiateXML.

Can you post the XML of your Objects/Cannonball.xml that you’re trying to instantiate?[/quote]

This is Cannonball.xml .

<?xml version="1.0"?> <node id="3"> <attribute name="Is Enabled" value="true" /> <attribute name="Name" value="Cannonball" /> <attribute name="Position" value="0 3.5 3.5" /> <attribute name="Rotation" value="1 0 0 0" /> <attribute name="Scale" value="1 1 1" /> <attribute name="Variables" /> <component type="StaticModel" id="12"> <attribute name="Model" value="Model;Models/Cannonball.mdl" /> <attribute name="Material" value="Material;Materials/Cannonball.xml" /> </component> <component type="ScriptInstance" id="14"> <attribute name="Delayed Method Calls" value="0" /> <attribute name="Script File" value="ScriptFile;Scripts/CannonBall.as" /> <attribute name="Class Name" value="Dying" /> <attribute name="time" value="0" /> </component> <component type="CollisionShape" id="15"> <attribute name="Shape Type" value="Sphere" /> <attribute name="Size" value="0.8 0.5 1" /> </component> <component type="RigidBody" id="16"> <attribute name="Physics Position" value="0 3.5 3.5" /> <attribute name="Mass" value="1" /> </component> </node>

From what I’m suspecting its either a null reference was returned for the rigid body when instantiated from xml or the Node@ reference held by the “node” attribute of the Canon ScriptClass was lost. Can you post the code of CanonBall.as, it might be a bit helpful.

CanonBall.as

class Dying : ScriptObject { float time = 0.0f; void Update(float timeStep) { time += timeStep; if (time > 10.0f) node.Remove(); } }