Entity::GetPosition Access Violation.

[martyj]

I have an Entity object passed from lua code via lua_touserdata

 

int Binder::RegisterClass(lua_State* L)
{
   Entity* entity = (Entity*)lua_touserdata(L, 1);
   const char* className_cstr = lua_tostring(L, 2);
   string className(className_cstr);

   Vec3 posit = entity->GetPosition();
}

 

The Lua code that calls this C code

 

function Script:Start()
   WorldFactions.RegisterClass(self.entity, "AnimatedModel");
end

 

I get an access violation on the line that is Vec3 posit = entity->GetPosition();

 

Below is a screenshot of the breakpoint on the same line before execution.

 

[MarkusR]

the last problem i had with .GetPosition()

it was this csg objects from toolbar made problem without have a script, it was not a entity object and something else i believe.

[martyj]

This object should be an Entity type considering how I am calling my C code from Lua. Unless I am passing the params wrong, the string passes correctly.

[AggrorJorn]

Any chance it is a CSG brush? Those get collapsed on scene loading for performace. Only when a script is attached these remain entities.

[Rick]

Any chance it is a CSG brush? Those get collapsed on scene loading for performace. Only when a script is attached these remain entities.

 

That's what I thought at first but he's passing self.entity inside an entity script (because of Script:Start() shown) which means even if it was it has a script attached to it which would prevent the collapse.

 

I'm not 100% sure if the Lua entity can be translated to an Entity in C++. You might want to try just passing it's string name and then in C++ find it via it's name for testing purposes. Of course this means each name has to be unique (which I'm a proponent for personally anyway).

[Ma-Shell]

I would guess as well that the LUA entity is not directly compatible with a C++-Entity (as Rick suggested). Your screenshot shows that the attributes have some rubbish values. So that object you are inspecting surely isn't a C++-Entity. Maybe there is a bit of an offset needed. I would try implementing the method Rick suggested and then looking at the different addresses the two methods yield and whether they are in any way coherent.

[martyj]

Thanks for the feedback guys. I will try Rick's suggestion. It should work without any problems.

[Chimera]

I am also getting an access violation when using the ->SetPosition/Fov commands in C++. Code in question(Posting the entire App::Start for completeness' sake) :

 

bool App::Start()
{
//Perform cfg checks. Sets screenres to 1920x1080 if they throw an error
try {
ScreenWidth = stoi(System::GetProperty("Screen Width", "1920"));
ScreenHeight = stoi(System::GetProperty("Screen Height", "1080"));
} catch (std::invalid_argument) {std::cout << "\n\nWaiter!!! There was a string in my Screen Res!\n\n";}

//Initialize Steamworks (optional)
if (!Steamworks::Initialize())
{
System::Print("Error: Failed to initialize Steam.");
return false;
}
//Create a window
window = Leadwerks::Window::Create("Game Window",0,0,ScreenWidth,ScreenHeight,Window::Titlebar);

//Create a context
context = Context::Create(window);

//Create a world
world = World::Create();

std::string mapname = System::GetProperty("map","Maps/G.map");
Map::Load(mapname);

//The culprits are right here----->
//cam->SetPosition(0, 5, 0);
//cam->SetFOV(90);


//Move the mouse to the center of the screen
window->SetMousePosition(context->GetWidth()/2,context->GetHeight()/2);
window->HideMouse();
return true;
}

 

I have tried debuging multiple times, and it always throws an access violation when those 2 lines are uncommented. It works perfectly fine if I just create a camera through the editor though, so I have no clue what is going on.

 

EDIT: Apparently my problem was I forgot to call Camera::Create on cam....... I am an idiot. ಠ_ಠ