Interactive example in panda3D

panda3D_example2.py

from direct.showbase.ShowBase import ShowBase
from panda3d.core import *
import math
from direct.task import Task
from panda3d.core import ClockObject

globalClock = ClockObject.getGlobalClock()

class MyApp(ShowBase):
    def __init__(self):
        ShowBase.__init__(self)

        # Load the environment model.
        self.scene = self.loader.loadModel("models/environment")
        self.scene.reparentTo(self.render)
        self.scene.setScale(0.25, 0.25, 0.25)
        self.scene.setPos(-8, 42, 0)

        # Add some lighting.
        self.dir_light = DirectionalLight("dir_light")
        self.dir_light.setColor((1, 1, 1, 1))
        self.dir_light_nodepath = self.render.attachNewNode(self.dir_light)
        self.dir_light_nodepath.setHpr(0, -60, 0)
        self.render.setLight(self.dir_light_nodepath)

        # Add ambient light.
        self.ambient_light = AmbientLight("ambient_light")
        self.ambient_light.setColor((0.2, 0.2, 0.2, 1))
        self.ambient_light_nodepath = self.render.attachNewNode(self.ambient_light)
        self.render.setLight(self.ambient_light_nodepath)

        # Disable the default mouse camera control and initialize key tracking
        self.disableMouse()
        self.key_map = {"left": 0, "right": 0, "forward": 0, "backward": 0}
        self.setup_key_controls()

        # Mouse control for camera rotation
        self.mouse_btn_down = False
        self.last_mouse_pos = (0, 0)
        self.accept("mouse1", self.set_mouse_btn_down, [True])
        self.accept("mouse1-up", self.set_mouse_btn_down, [False])
        self.taskMgr.add(self.update_camera_rotation, "update_camera_rotation")

        # Movement task
        self.taskMgr.add(self.update_movement, "update_movement")

    def setup_key_controls(self):
        self.accept("arrow_left", self.update_key_map, ["left", True])
        self.accept("arrow_right", self.update_key_map, ["right", True])
        self.accept("arrow_up", self.update_key_map, ["forward", True])
        self.accept("arrow_down", self.update_key_map, ["backward", True])
        self.accept("arrow_left-up", self.update_key_map, ["left", False])
        self.accept("arrow_right-up", self.update_key_map, ["right", False])
        self.accept("arrow_up-up", self.update_key_map, ["forward", False])
        self.accept("arrow_down-up", self.update_key_map, ["backward", False])

    def update_key_map(self, key, value):
        self.key_map[key] = value

    def update_movement(self, task):
        dt = globalClock.getDt()
        # print(dt)
        speed = 10.0

        # Calculate the camera's forward and right vectors
        forward_vec = self.camera.getNetTransform().getMat().getRow3(1)
        right_vec = self.camera.getNetTransform().getMat().getRow3(0)
        forward_vec.normalize()
        right_vec.normalize()

        if self.key_map["forward"]:
            self.camera.setPos(self.camera.getPos() + forward_vec * speed * dt)
        if self.key_map["backward"]:
            self.camera.setPos(self.camera.getPos() - forward_vec * speed * dt)
        if self.key_map["left"]:
            self.camera.setPos(self.camera.getPos() - right_vec * speed * dt)
        if self.key_map["right"]:
            self.camera.setPos(self.camera.getPos() + right_vec * speed * dt)

        return task.cont

    def set_mouse_btn_down(self, down):
        self.mouse_btn_down = down
        if not down:
            self.last_mouse_pos = (0, 0)  # Reset last mouse position

    def update_camera_rotation(self, task):
        if self.mouse_btn_down and self.mouseWatcherNode.hasMouse():
            x, y = self.mouseWatcherNode.getMouseX(), self.mouseWatcherNode.getMouseY()
            if self.last_mouse_pos != (0, 0):
                delta_x, delta_y = x - self.last_mouse_pos[0], y - self.last_mouse_pos[1]
                self.camera.setH(self.camera.getH() - delta_x * 100)  # Horizontal rotation
                self.camera.setP(self.camera.getP() + delta_y * 100)  # Vertical rotation, sign inverted
            self.last_mouse_pos = (x, y)
        return task.cont


app = MyApp()
app.run()