Using Panda3D without "direct"

Code Snippets
#1

This is a minimal sample program showing how to open a window and render a model without using ShowBase, or indeed, any part of the direct module. This may be useful for certain low-level usage of Panda where ShowBase would just get in the way, or just for better understanding Panda under the hood.

from panda3d.core import *

engine = GraphicsEngine.get_global_ptr()
pipe = GraphicsPipeSelection.get_global_ptr().make_default_pipe()

# Open a window with requested properties
fb_prop = FrameBufferProperties()
fb_prop.rgb_color = 1
fb_prop.color_bits = 3 * 8
fb_prop.depth_bits = 24
fb_prop.back_buffers = 1
win = engine.make_output(pipe, name="window", sort=0, fb_prop=fb_prop,
                         win_prop=WindowProperties(size=(800, 600)),
                         flags=GraphicsPipe.BF_require_window)

# Set a grey background color
win.set_clear_color_active(True)
win.set_clear_color((0.5, 0.5, 0.5, 1))

# Create a scene and camera to render
render = NodePath("render")
cam = render.attach_new_node(Camera("camera"))
cam.node().set_lens(PerspectiveLens())

# Load a model into the scene
loader = Loader.get_global_ptr()
model = render.attach_new_node(loader.load_sync("panda.egg"))
model.set_pos(0, 100, 0)

# Create a display region that renders this scene
dr = win.make_display_region()
dr.camera = cam

# You could use the task manager and create a task that does this,
# but I wanted to show how to do it directly
while not win.is_closed():
    engine.render_frame()
6 Likes
#2

Neat! So “direct” is just a big collection of utility functions?

#3

“direct” - think of it as a library with game features.
“ShowBase” - the application template.

#4

Sort of—the intent of “direct” is that it makes it really easy to create prototypes with the aid of a bunch of high-level Python classes that are easier to use than the C++ lower-level classes.

You can do pretty much anything you can do with direct directly with panda3d.core as well, it just takes more code.

#5

I’m wondering why the model looks flattened and flat. Is it because of the lack of a depth buffer?

#6

Yes! Good catch. Updated the code to request a depth buffer.

#7

There is still not enough input device for the window.