scene_loading.py

#!/usr/bin/env python

import sys

from direct.showbase.ShowBase import ShowBase
from direct.gui.OnscreenText import OnscreenText
from panda3d.core import PointLight, VBase4, DirectionalLight, LVector3f, LPoint3f, Vec3, GeomEnums, GeomNode, TransformState, NodePath
from panda3d.bullet import BulletWorld, BulletTriangleMesh, BulletRigidBodyNode, BulletTriangleMeshShape, BulletConvexHullShape, BulletPlaneShape, BulletBoxShape, BulletDebugNode


class MyApp(ShowBase):

    def __init__(self):
        ShowBase.__init__(self)
        self.text = None
        self.rebuild()
        self.accept('escape', sys.exit)
        self.accept('f', self.toggleWireframe)
        self.accept('r', self.rebuild)
        self.taskMgr.add(self.update, 'update')

    def rebuild(self):
        self.clean()
        if self.load_dynamic_body == self.load_dynamic_body1:
            self.load_dynamic_body = self.load_dynamic_body2
            self.text = OnscreenText(text = 'With triangle mesh (press r to change)', pos = (-0.5, 0.5))
        else:
            self.load_dynamic_body = self.load_dynamic_body1
            self.text = OnscreenText(text = 'With convex hull (press r to change)', pos = (-0.5, 0.5))
        self.world = BulletWorld()
        self.world.setGravity(Vec3(0, 0, -9.81))
        debugNP = self.render.attachNewNode(BulletDebugNode('Debug'))
        debugNP.show()
        self.world.setDebugNode(debugNP.node())
        self.load_scene('myscene')
        self.cam.setPos(10, 10, 10)
        self.cam.lookAt(0, 0, 0)

    def clean(self):
        for child in self.render.getChildren():
            if child.getName() != 'camera':
                child.removeNode()
        if self.text:
            self.text.removeNode()

    def update(self, task):
        dt = globalClock.getDt()
        self.world.doPhysics(dt/3)
        return task.cont

    def load_scene(self, filename):
        scene_root_np = self.loader.loadModel(filename)
        scene_root_np.flattenLight()

        for object_root_np in scene_root_np.findAllMatches('**/coll_dyn*'):
            self.load_dynamic_body(scene_root_np, object_root_np, mass=1)

        for object_root_np in scene_root_np.findAllMatches('**/coll_stat*'):
            self.load_static_body(scene_root_np, object_root_np)

        for object_root_np in scene_root_np.findAllMatches('**/coll_ghost*'):
            self.load_ghost(scene_root_np, object_root_np)

        self.render.ls()

    def load_dynamic_body1(self, scene_root_np, object_root_np, mass):
        body = BulletRigidBodyNode('BodyNode')
        for geom_np in object_root_np.findAllMatches('**/+GeomNode'):
            shape = BulletConvexHullShape()
            for geom in geom_np.node().getGeoms():
                geom = geom.decompose()
                shape.addGeom(geom)
            body.addShape(shape)
        body.setMass(mass)
        body_np = self.render.attachNewNode(body)
        object_root_np.reparentTo(body_np)
        self.world.attachRigidBody(body)

    def load_dynamic_body2(self, scene_root_np, object_root_np, mass):
        body = BulletRigidBodyNode('BodyNode')
        for geom_np in object_root_np.findAllMatches('**/+GeomNode'):
            triangle_geom = BulletTriangleMesh()
            for geom in geom_np.node().getGeoms():
                geom = geom.decompose()
                triangle_geom.addGeom(geom)
        shape = BulletTriangleMeshShape(triangle_geom, dynamic=(mass==0))
        body.addShape(shape)
        body.setMass(mass)
        body_np = self.render.attachNewNode(body)
        object_root_np.reparentTo(body_np)
        self.world.attachRigidBody(body)

    def load_static_body(self, scene_root_np, object_root_np):
        return self.load_dynamic_body(scene_root_np, object_root_np, mass=0)

    def load_ghost(self, scene_root_np, object_root_np):
        object_root_np.reparentTo(self.render)

    load_dynamic_body = load_dynamic_body1

app = MyApp()
app.run()