Loading Models

The Basics

Loading static geometry is done using window->load_model:

NodePath m = window->load_model(framework.get_models(), "mymodel.egg");

The path name specified in loadModel can be an absolute path, or a relative path. Relative is recommended. If a relative path is used, then Panda3D will search its model path to find the egg file. The model path is controlled by panda’s configuration file.

Inserting the Model into the Scene Graph

Do not forget that loading the model does not, by itself, cause the model to be visible. To cause Panda3D to render the model, you must insert it into the scene graph:


You can read more about The Scene Graph.

Panda Filename Syntax

The path used in the model load call must abide by Panda3D’s filename conventions. For easier portability, Panda3D uses Unix-style pathnames, even on Microsoft Windows. This means that the directory separator character is always a forward slash, not the Windows backslash character, and there is no leading drive letter prefix. (Instead of a leading drive letter, Panda uses an initial one-letter directory name to represent the drive.)

There is a fairly straightforward conversion from Windows filenames to panda filenames. Always be sure to use Panda filename syntax when using a Panda3D library function, or one of the panda utility programs:

window->load_model(framework.get_models(), "c:\\Program Files\\My Game\\Models\\Model1.egg");

window->load_model(framework.get_models(), "/c/Program Files/My Game/Models/Model1.egg");

Panda uses the Filename class to store Panda-style filenames; many Panda functions expect a Filename object as a parameter. The Filename class also contains several useful methods for path manipulation and file access, as well as for converting between Windows-style filenames and Panda-style filenames; see the Filename page in the API Reference for a more complete list.

To convert a Windows filename to a Panda pathname, use code similar to the following:

#include "filename.h"

const std::string winfile = "c:\\MyGame\\Model1.egg";
Filename pandafile = Filename::from_os_specific(winfile);
std::cout << pandafile.get_fullpath() << "\n";

To convert a Panda filename into a Windows filename, use code like this:

#include "filename.h"

Filename pandafile ("/c/MyGame/Model1.egg");
const std::string winfile = pandafile.to_os_specific();
std::cout << winfile << "\n";

The Filename class can also be used in combination with python’s built-in path manipulation mechanisms.

Let’s say, for instance, that you want to load a model, and the model is in the “model” directory that is in the same directory as the program’s main file.

Here is how you would load the model:

#include "filename.h"
#include "executionEnvironment.h"

// Get the location of the executable file I'm running:
Filename mydir = ExecutionEnvironment::get_binary_name();
mydir = mydir.get_dirname();

// Now load the model:
window->load_model(framework.get_models(), mydir + "/models/mymodel.egg");

You need to keep in mind that standard library functions provided by the system or the programming language runtime work with OS-specific paths. So do not forget to convert your Panda paths to OS-specific paths when using these built- in functions. In cases where Panda’s API offers equivalent functions through the Filename or VirtualFileSystem class, however, it is recommended to use those instead, as they will natively understand Panda Filenames.