class World(DirectObject):
def __init__(self):
self.keyMap = {"left":0, "right":0, "forward":0, "cam-left":0, "cam-right":0}
base.win.setClearColor(Vec4(0,0,0,1))
# Post the instructions
self.title = addTitle("Panda3D Tutorial: Roaming Ralph (Walking on Uneven Terrain)")
self.inst1 = addInstructions(0.95, "[ESC]: Quit")
self.inst2 = addInstructions(0.90, "[Left Arrow]: Rotate Ralph Left")
self.inst3 = addInstructions(0.85, "[Right Arrow]: Rotate Ralph Right")
self.inst4 = addInstructions(0.80, "[Up Arrow]: Run Ralph Forward")
self.inst6 = addInstructions(0.70, "[A]: Rotate Camera Left")
self.inst7 = addInstructions(0.65, "[S]: Rotate Camera Right")
# Set up the environment
#
# This environment model contains collision meshes. If you look
# in the egg file, you will see the following:
#
# <Collide> { Polyset keep descend }
#
# This tag causes the following mesh to be converted to a collision
# mesh -- a mesh which is optimized for collision, not rendering.
# It also keeps the original mesh, so there are now two copies ---
# one optimized for rendering, one for collisions.
self.environ = loader.loadModel("models/samples/roaming_ralph/world")
self.environ.reparentTo(render)
self.environ.setPos(0,0,0)
# Create the main character, Ralph
ralphStartPos = self.environ.find("**/start_point").getPos()
self.ralph = Actor("models/samples/roaming_ralph/ralph",
{"run":"models/samples/roaming_ralph/ralph_run",
"walk":"models/samples/roaming_ralph/ralph_walk"})
self.ralph.reparentTo(render)
self.ralph.setScale(.2)
self.ralph.setPos(ralphStartPos)
# Create a floater object. We use the "floater" as a temporary
# variable in a variety of calculations.
self.floater = NodePath(PandaNode("floater"))
self.floater.reparentTo(render)
# Accept the control keys for movement and rotation
self.accept("escape", sys.exit)
self.accept("arrow_left", self.setKey, ["left",1])
self.accept("arrow_right", self.setKey, ["right",1])
self.accept("arrow_up", self.setKey, ["forward",1])
self.accept("a", self.setKey, ["cam-left",1])
self.accept("s", self.setKey, ["cam-right",1])
self.accept("arrow_left-up", self.setKey, ["left",0])
self.accept("arrow_right-up", self.setKey, ["right",0])
self.accept("arrow_up-up", self.setKey, ["forward",0])
self.accept("a-up", self.setKey, ["cam-left",0])
self.accept("s-up", self.setKey, ["cam-right",0])
taskMgr.add(self.move,"moveTask")
# Game state variables
self.isMoving = False
# Set up the camera
base.disableMouse()
base.camera.setPos(self.ralph.getX(),self.ralph.getY()+10,2)
# We will detect the height of the terrain by creating a collision
# ray and casting it downward toward the terrain. One ray will
# start above ralph's head, and the other will start above the camera.
# A ray may hit the terrain, or it may hit a rock or a tree. If it
# hits the terrain, we can detect the height. If it hits anything
# else, we rule that the move is illegal.
self.cTrav = CollisionTraverser()
self.ralphGroundRay = CollisionRay()
self.ralphGroundRay.setOrigin(0,0,1000)
self.ralphGroundRay.setDirection(0,0,-1)
self.ralphGroundCol = CollisionNode('ralphRay')
self.ralphGroundCol.addSolid(self.ralphGroundRay)
self.ralphGroundCol.setFromCollideMask(BitMask32.bit(0))
self.ralphGroundCol.setIntoCollideMask(BitMask32.allOff())
self.ralphGroundColNp = self.ralph.attachNewNode(self.ralphGroundCol)
self.ralphGroundHandler = CollisionHandlerQueue()
self.cTrav.addCollider(self.ralphGroundColNp, self.ralphGroundHandler)
self.camGroundRay = CollisionRay()
self.camGroundRay.setOrigin(0,0,1000)
self.camGroundRay.setDirection(0,0,-1)
self.camGroundCol = CollisionNode('camRay')
self.camGroundCol.addSolid(self.camGroundRay)
self.camGroundCol.setFromCollideMask(BitMask32.bit(0))
self.camGroundCol.setIntoCollideMask(BitMask32.allOff())
self.camGroundColNp = base.camera.attachNewNode(self.camGroundCol)
self.camGroundHandler = CollisionHandlerQueue()
self.cTrav.addCollider(self.camGroundColNp, self.camGroundHandler)
# Uncomment this line to see the collision rays
#self.ralphGroundColNp.show()
#self.camGroundColNp.show()
#Uncomment this line to show a visual representation of the
#collisions occuring
#self.cTrav.showCollisions(render)
#Records the state of the arrow keys
def setKey(self, key, value):
self.keyMap[key] = value
# Accepts arrow keys to move either the player or the menu cursor,
# Also deals with grid checking and collision detection
def move(self, task):
# Get the time elapsed since last frame. We need this
# for framerate-independent movement.
elapsed = globalClock.getDt()
# If the camera-left key is pressed, move camera left.
# If the camera-right key is pressed, move camera right.
base.camera.lookAt(self.ralph)
if (self.keyMap["cam-left"]!=0):
base.camera.setX(base.camera, -(elapsed*20))
if (self.keyMap["cam-right"]!=0):
base.camera.setX(base.camera, +(elapsed*20))
# save ralph's initial position so that we can restore it,
# in case he falls off the map or runs into something.
startpos = self.ralph.getPos()
# If a move-key is pressed, move ralph in the specified direction.
if (self.keyMap["left"]!=0):
self.ralph.setH(self.ralph.getH() + elapsed*300)
if (self.keyMap["right"]!=0):
self.ralph.setH(self.ralph.getH() - elapsed*300)
if (self.keyMap["forward"]!=0):
self.ralph.setY(self.ralph, -(elapsed*25))
# If ralph is moving, loop the run animation.
# If he is standing still, stop the animation.
if (self.keyMap["forward"]!=0) or (self.keyMap["left"]!=0) or (self.keyMap["right"]!=0):
if self.isMoving is False:
self.ralph.loop("run")
self.isMoving = True
else:
if self.isMoving:
self.ralph.stop()
self.ralph.pose("walk",5)
self.isMoving = False
# If the camera is too far from ralph, move it closer.
# If the camera is too close to ralph, move it farther.
camvec = self.ralph.getPos() - base.camera.getPos()
camvec.setZ(0)
camdist = camvec.length()
camvec.normalize()
if (camdist > 10.0):
base.camera.setPos(base.camera.getPos() + camvec*(camdist-10))
camdist = 10.0
if (camdist < 5.0):
base.camera.setPos(base.camera.getPos() - camvec*(5-camdist))
camdist = 5.0
# Now check for collisions.
self.cTrav.traverse(render)
# Adjust ralph's Z coordinate. If ralph's ray hit terrain,
# update his Z. If it hit anything else, or didn't hit anything, put
# him back where he was last frame.
entries = []
for i in range(self.ralphGroundHandler.getNumEntries()):
entry = self.ralphGroundHandler.getEntry(i)
entries.append(entry)
entries.sort(lambda x,y: cmp(y.getSurfacePoint(render).getZ(),
x.getSurfacePoint(render).getZ()))
if (len(entries)>0) and (entries[0].getIntoNode().getName() == "terrain"):
self.ralph.setZ(entries[0].getSurfacePoint(render).getZ())
else:
self.ralph.setPos(startpos)
# Keep the camera at one foot above the terrain,
# or two feet above ralph, whichever is greater.
entries = []
for i in range(self.camGroundHandler.getNumEntries()):
entry = self.camGroundHandler.getEntry(i)
entries.append(entry)
entries.sort(lambda x,y: cmp(y.getSurfacePoint(render).getZ(),
x.getSurfacePoint(render).getZ()))
if (len(entries)>0) and (entries[0].getIntoNode().getName() == "terrain"):
base.camera.setZ(entries[0].getSurfacePoint(render).getZ()+1.0)
if (base.camera.getZ() < self.ralph.getZ() + 2.0):
base.camera.setZ(self.ralph.getZ() + 2.0)
# The camera should look in ralph's direction,
# but it should also try to stay horizontal, so look at
# a floater which hovers above ralph's head.
self.floater.setPos(self.ralph.getPos())
self.floater.setZ(self.ralph.getZ() + 2.0)
base.camera.lookAt(self.floater)
return Task.cont
class World(DirectObject):
def __init__(self):
#This code puts the standard title and instruction text on screen
self.title = OnscreenText(text="Panda3D: Tutorial - Collision Detection",
style=1, fg=(1,1,1,1),
pos=(0.7,-0.95), scale = .07, font = font)
self.instructions = OnscreenText(text="Mouse pointer tilts the board",
pos = (-1.3, .95), fg=(1,1,1,1), font = font,
align = TextNode.ALeft, scale = .05)
self.accept("escape", sys.exit) #Escape quits
base.disableMouse() #Disable mouse-based camera control
camera.setPosHpr(0, 0, 25, 0, -90, 0) #Place the camera
#Load the maze and place it in the scene
self.maze = loader.loadModel("models/samples/ball_in_maze/maze")
self.maze.reparentTo(render)
#Most times, you want collisions to be tested against invisible geometry
#rather than every polygon. This is because testing against every polygon
#in the scene is usually too slow. You can have simplified or approximate
#geometry for the solids and still get good results.
#
#Sometimes you'll want to create and position your own collision solids in
#code, but it's often easier to have them built automatically. This can be
#done by adding special tags into an egg file. Check maze.egg and ball.egg
#and look for lines starting with <Collide>. The part is brackets tells
#Panda exactly what to do. Polyset means to use the polygons in that group
#as solids, while Sphere tells panda to make a collision sphere around them
#Keep means to keep the polygons in the group as visable geometry (good
#for the ball, not for the triggers), and descend means to make sure that
#the settings are applied to any subgroups.
#
#Once we have the collision tags in the models, we can get to them using
#NodePath's find command
#Find the collision node named wall_collide
self.walls = self.maze.find("**/wall_collide")
#Collision objects are sorted using BitMasks. BitMasks are ordinary numbers
#with extra methods for working with them as binary bits. Every collision
#solid has both a from mask and an into mask. Before Panda tests two
#objects, it checks to make sure that the from and into collision masks
#have at least one bit in common. That way things that shouldn't interact
#won't. Normal model nodes have collision masks as well. By default they
#are set to bit 20. If you want to collide against actual visable polygons,
#set a from collide mask to include bit 20
#
#For this example, we will make everything we want the ball to collide with
#include bit 0
self.walls.node().setIntoCollideMask(BitMask32.bit(0))
#CollisionNodes are usually invisible but can be shown. Uncomment the next
#line to see the collision walls
#self.walls.show()
#We will now find the triggers for the holes and set their masks to 0 as
#well. We also set their names to make them easier to identify during
#collisions
self.loseTriggers = []
for i in range(6):
trigger = self.maze.find("**/hole_collide" + str(i))
trigger.node().setIntoCollideMask(BitMask32.bit(0))
trigger.node().setName("loseTrigger")
self.loseTriggers.append(trigger)
#Uncomment this line to see the triggers
#trigger.show()
#Ground_collide is a single polygon on the same plane as the ground in the
#maze. We will use a ray to collide with it so that we will know exactly
#what height to put the ball at every frame. Since this is not something
#that we want the ball itself to collide with, it has a different
#bitmask.
self.mazeGround = self.maze.find("**/ground_collide")
self.mazeGround.node().setIntoCollideMask(BitMask32.bit(1))
#Load the ball and attach it to the scene
#It is on a root dummy node so that we can rotate the ball itself without
#rotating the ray that will be attached to it
self.ballRoot = render.attachNewNode("ballRoot")
self.ball = loader.loadModel("models/samples/ball_in_maze/ball")
self.ball.reparentTo(self.ballRoot)
#Find the collison sphere for the ball which was created in the egg file
#Notice that it has a from collision mask of bit 0, and an into collison
#mask of no bits. This means that the ball can only cause collisions, not
#be collided into
self.ballSphere = self.ball.find("**/ball")
self.ballSphere.node().setFromCollideMask(BitMask32.bit(0))
self.ballSphere.node().setIntoCollideMask(BitMask32.allOff())
#No we create a ray to start above the ball and cast down. This is to
#Determine the height the ball should be at and the angle the floor is
#tilting. We could have used the sphere around the ball itself, but it
#would not be as reliable
self.ballGroundRay = CollisionRay() #Create the ray
self.ballGroundRay.setOrigin(0,0,10) #Set its origin
self.ballGroundRay.setDirection(0,0,-1) #And its direction
#Collision solids go in CollisionNode
self.ballGroundCol = CollisionNode('groundRay') #Create and name the node
self.ballGroundCol.addSolid(self.ballGroundRay) #Add the ray
self.ballGroundCol.setFromCollideMask(BitMask32.bit(1)) #Set its bitmasks
self.ballGroundCol.setIntoCollideMask(BitMask32.allOff())
#Attach the node to the ballRoot so that the ray is relative to the ball
#(it will always be 10 feet over the ball and point down)
self.ballGroundColNp = self.ballRoot.attachNewNode(self.ballGroundCol)
#Uncomment this line to see the ray
#self.ballGroundColNp.show()
#Finally, we create a CollisionTraverser. CollisionTraversers are what
#do the job of calculating collisions
self.cTrav = CollisionTraverser()
#Collision traverservs tell collision handlers about collisions, and then
#the handler decides what to do with the information. We are using a
#CollisionHandlerQueue, which simply creates a list of all of the
#collisions in a given pass. There are more sophisticated handlers like
#one that sends events and another that tries to keep collided objects
#apart, but the results are often better with a simple queue
self.cHandler = CollisionHandlerQueue()
#Now we add the collision nodes that can create a collision to the
#traverser. The traverser will compare these to all others nodes in the
#scene. There is a limit of 32 CollisionNodes per traverser
#We add the collider, and the handler to use as a pair
self.cTrav.addCollider(self.ballSphere, self.cHandler)
self.cTrav.addCollider(self.ballGroundColNp, self.cHandler)
#Collision traversers have a built in tool to help visualize collisions.
#Uncomment the next line to see it.
#self.cTrav.showCollisions(render)
#This section deals with lighting for the ball. Only the ball was lit
#because the maze has static lighting pregenerated by the modeler
lAttrib = LightAttrib.makeAllOff()
ambientLight = AmbientLight( "ambientLight" )
ambientLight.setColor( Vec4(.55, .55, .55, 1) )
lAttrib = lAttrib.addLight( ambientLight )
directionalLight = DirectionalLight( "directionalLight" )
directionalLight.setDirection( Vec3( 0, 0, -1 ) )
directionalLight.setColor( Vec4( 0.375, 0.375, 0.375, 1 ) )
directionalLight.setSpecularColor(Vec4(1,1,1,1))
lAttrib = lAttrib.addLight( directionalLight )
self.ballRoot.node().setAttrib( lAttrib )
#This section deals with adding a specular highlight to the ball to make
#it look shiny
m = Material()
m.setSpecular(Vec4(1,1,1,1))
m.setShininess(96)
self.ball.setMaterial(m, 1)
#Finally, we call start for more initialization
self.start()
def start(self):
#The maze model also has a locator in it for where to start the ball
#To access it we use the find command
startPos = self.maze.find("**/start").getPos()
self.ballRoot.setPos(startPos) #Set the ball in the starting position
self.ballV = Vec3(0,0,0) #Initial velocity is 0
self.accelV = Vec3(0,0,0) #Initial acceleration is 0
#For a traverser to actually do collisions, you need to call
#traverser.traverse() on a part of the scene. Fortunatly, base has a
#task that does this for the entire scene once a frame. This sets up our
#traverser as the one to be called automatically
base.cTrav = self.cTrav
#Create the movement task, but first make sure it is not already running
taskMgr.remove("rollTask")
self.mainLoop = taskMgr.add(self.rollTask, "rollTask")
self.mainLoop.last = 0
#This function handles the collision between the ray and the ground
#Information about the interaction is passed in colEntry
def groundCollideHandler(self, colEntry):
#Set the ball to the appropriate Z value for it to be exactly on the ground
newZ = colEntry.getSurfacePoint(render).getZ()
self.ballRoot.setZ(newZ+.4)
#Find the acceleration direction. First the surface normal is crossed with
#the up vector to get a vector perpendicular to the slope
norm = colEntry.getSurfaceNormal(render)
accelSide = norm.cross(UP)
#Then that vector is crossed with the surface normal to get a vector that
#points down the slope. By getting the acceleration in 3D like this rather
#than in 2D, we reduce the amount of error per-frame, reducing jitter
self.accelV = norm.cross(accelSide)
#This function handles the collision between the ball and a wall
def wallCollideHandler(self, colEntry):
#First we calculate some numbers we need to do a reflection
norm = colEntry.getSurfaceNormal(render) * -1 #The normal of the wall
curSpeed = self.ballV.length() #The current speed
inVec = self.ballV / curSpeed #The direction of travel
velAngle = norm.dot(inVec) #Angle of incidance
hitDir = colEntry.getSurfacePoint(render) - self.ballRoot.getPos()
hitDir.normalize()
hitAngle = norm.dot(hitDir) #The angle between the ball and the normal
#Ignore the collision if the ball is either moving away from the wall
#already (so that we don't accidentally send it back into the wall)
#and ignore it if the collision isn't dead-on (to avoid getting caught on
#corners)
if velAngle > 0 and hitAngle > .995:
#Standard reflection equation
reflectVec = (norm * norm.dot(inVec * -1) * 2) + inVec
#This makes the velocity half of what it was if the hit was dead-on
#and nearly exactly what it was if this is a glancing blow
self.ballV = reflectVec * (curSpeed * (((1-velAngle)*.5)+.5))
#Since we have a collision, the ball is already a little bit buried in
#the wall. This calculates a vector needed to move it so that it is
#exactly touching the wall
disp = (colEntry.getSurfacePoint(render) -
colEntry.getInteriorPoint(render))
newPos = self.ballRoot.getPos() + disp
self.ballRoot.setPos(newPos)
#This is the task that deals with making everything interactive
def rollTask(self, task):
#Standard technique for finding the amount of time since the last frame
dt = task.time - task.last
task.last = task.time
#If dt is large, then there has been a #hiccup that could cause the ball
#to leave the field if this functions runs, so ignore the frame
if dt > .2: return Task.cont
#The collision handler collects the collisions. We dispatch which function
#to handle the collision based on the name of what was collided into
for i in range(self.cHandler.getNumEntries()):
entry = self.cHandler.getEntry(i)
name = entry.getIntoNode().getName()
if name == "wall_collide": self.wallCollideHandler(entry)
elif name == "ground_collide": self.groundCollideHandler(entry)
elif name == "loseTrigger": self.loseGame(entry)
#Read the mouse position and tilt the maze accordingly
if base.mouseWatcherNode.hasMouse():
mpos = base.mouseWatcherNode.getMouse() #get the mouse position
self.maze.setP(mpos.getY() * -10)
self.maze.setR(mpos.getX() * 10)
#Finally, we move the ball
#Update the velocity based on acceleration
self.ballV += self.accelV * dt * ACCEL
#Clamp the velocity to the maximum speed
if self.ballV.lengthSquared() > MAX_SPEED_SQ:
self.ballV.normalize()
self.ballV *= MAX_SPEED
#Update the position based on the velocity
self.ballRoot.setPos(self.ballRoot.getPos() + (self.ballV * dt))
#This block of code rotates the ball. It uses something called a quaternion
#to rotate the ball around an arbitrary axis. That axis perpendicular to
#the balls rotation, and the amount has to do with the size of the ball
#This is multiplied on the previous rotation to incrimentally turn it.
prevRot = LRotationf(self.ball.getQuat())
axis = UP.cross(self.ballV)
newRot = LRotationf(axis, 45.5 * dt * self.ballV.length())
self.ball.setQuat(prevRot * newRot)
return Task.cont #Continue the task indefinitely
#If the ball hits a hole trigger, then it should fall in the hole.
#This is faked rather than dealing with the actual physics of it.
def loseGame(self, entry):
#The triggers are set up so that the center of the ball should move to the
#collision point to be in the hole
toPos = entry.getInteriorPoint(render)
taskMgr.remove('rollTask') #Stop the maze task
#Move the ball into the hole over a short sequence of time. Then wait a
#second and call start to reset the game
Sequence(
Parallel(
LerpFunc(self.ballRoot.setX, fromData = self.ballRoot.getX(),
toData = toPos.getX(), duration = .1),
LerpFunc(self.ballRoot.setY, fromData = self.ballRoot.getY(),
toData = toPos.getY(), duration = .1),
LerpFunc(self.ballRoot.setZ, fromData = self.ballRoot.getZ(),
toData = self.ballRoot.getZ() - .9, duration = .2)),
Wait(1),
Func(self.start)).start()
class World(DirectObject):
def __init__(self):
#This code puts the standard title and instruction text on screen
self.title = OnscreenText(
text="Panda3D: Tutorial - Collision Detection",
style=1,
fg=(1, 1, 1, 1),
pos=(0.7, -0.95),
scale=.07,
font=font)
self.instructions = OnscreenText(text="Mouse pointer tilts the board",
pos=(-1.3, .95),
fg=(1, 1, 1, 1),
font=font,
align=TextNode.ALeft,
scale=.05)
self.accept("escape", sys.exit) #Escape quits
base.disableMouse() #Disable mouse-based camera control
camera.setPosHpr(0, 0, 25, 0, -90, 0) #Place the camera
#Load the maze and place it in the scene
self.maze = loader.loadModel("models/samples/ball_in_maze/maze")
self.maze.reparentTo(render)
#Most times, you want collisions to be tested against invisible geometry
#rather than every polygon. This is because testing against every polygon
#in the scene is usually too slow. You can have simplified or approximate
#geometry for the solids and still get good results.
#
#Sometimes you'll want to create and position your own collision solids in
#code, but it's often easier to have them built automatically. This can be
#done by adding special tags into an egg file. Check maze.egg and ball.egg
#and look for lines starting with <Collide>. The part is brackets tells
#Panda exactly what to do. Polyset means to use the polygons in that group
#as solids, while Sphere tells panda to make a collision sphere around them
#Keep means to keep the polygons in the group as visable geometry (good
#for the ball, not for the triggers), and descend means to make sure that
#the settings are applied to any subgroups.
#
#Once we have the collision tags in the models, we can get to them using
#NodePath's find command
#Find the collision node named wall_collide
self.walls = self.maze.find("**/wall_collide")
#Collision objects are sorted using BitMasks. BitMasks are ordinary numbers
#with extra methods for working with them as binary bits. Every collision
#solid has both a from mask and an into mask. Before Panda tests two
#objects, it checks to make sure that the from and into collision masks
#have at least one bit in common. That way things that shouldn't interact
#won't. Normal model nodes have collision masks as well. By default they
#are set to bit 20. If you want to collide against actual visable polygons,
#set a from collide mask to include bit 20
#
#For this example, we will make everything we want the ball to collide with
#include bit 0
self.walls.node().setIntoCollideMask(BitMask32.bit(0))
#CollisionNodes are usually invisible but can be shown. Uncomment the next
#line to see the collision walls
#self.walls.show()
#We will now find the triggers for the holes and set their masks to 0 as
#well. We also set their names to make them easier to identify during
#collisions
self.loseTriggers = []
for i in range(6):
trigger = self.maze.find("**/hole_collide" + str(i))
trigger.node().setIntoCollideMask(BitMask32.bit(0))
trigger.node().setName("loseTrigger")
self.loseTriggers.append(trigger)
#Uncomment this line to see the triggers
#trigger.show()
#Ground_collide is a single polygon on the same plane as the ground in the
#maze. We will use a ray to collide with it so that we will know exactly
#what height to put the ball at every frame. Since this is not something
#that we want the ball itself to collide with, it has a different
#bitmask.
self.mazeGround = self.maze.find("**/ground_collide")
self.mazeGround.node().setIntoCollideMask(BitMask32.bit(1))
#Load the ball and attach it to the scene
#It is on a root dummy node so that we can rotate the ball itself without
#rotating the ray that will be attached to it
self.ballRoot = render.attachNewNode("ballRoot")
self.ball = loader.loadModel("models/samples/ball_in_maze/ball")
self.ball.reparentTo(self.ballRoot)
#Find the collison sphere for the ball which was created in the egg file
#Notice that it has a from collision mask of bit 0, and an into collison
#mask of no bits. This means that the ball can only cause collisions, not
#be collided into
self.ballSphere = self.ball.find("**/ball")
self.ballSphere.node().setFromCollideMask(BitMask32.bit(0))
self.ballSphere.node().setIntoCollideMask(BitMask32.allOff())
#No we create a ray to start above the ball and cast down. This is to
#Determine the height the ball should be at and the angle the floor is
#tilting. We could have used the sphere around the ball itself, but it
#would not be as reliable
self.ballGroundRay = CollisionRay() #Create the ray
self.ballGroundRay.setOrigin(0, 0, 10) #Set its origin
self.ballGroundRay.setDirection(0, 0, -1) #And its direction
#Collision solids go in CollisionNode
self.ballGroundCol = CollisionNode(
'groundRay') #Create and name the node
self.ballGroundCol.addSolid(self.ballGroundRay) #Add the ray
self.ballGroundCol.setFromCollideMask(
BitMask32.bit(1)) #Set its bitmasks
self.ballGroundCol.setIntoCollideMask(BitMask32.allOff())
#Attach the node to the ballRoot so that the ray is relative to the ball
#(it will always be 10 feet over the ball and point down)
self.ballGroundColNp = self.ballRoot.attachNewNode(self.ballGroundCol)
#Uncomment this line to see the ray
#self.ballGroundColNp.show()
#Finally, we create a CollisionTraverser. CollisionTraversers are what
#do the job of calculating collisions
self.cTrav = CollisionTraverser()
#Collision traverservs tell collision handlers about collisions, and then
#the handler decides what to do with the information. We are using a
#CollisionHandlerQueue, which simply creates a list of all of the
#collisions in a given pass. There are more sophisticated handlers like
#one that sends events and another that tries to keep collided objects
#apart, but the results are often better with a simple queue
self.cHandler = CollisionHandlerQueue()
#Now we add the collision nodes that can create a collision to the
#traverser. The traverser will compare these to all others nodes in the
#scene. There is a limit of 32 CollisionNodes per traverser
#We add the collider, and the handler to use as a pair
self.cTrav.addCollider(self.ballSphere, self.cHandler)
self.cTrav.addCollider(self.ballGroundColNp, self.cHandler)
#Collision traversers have a built in tool to help visualize collisions.
#Uncomment the next line to see it.
#self.cTrav.showCollisions(render)
#This section deals with lighting for the ball. Only the ball was lit
#because the maze has static lighting pregenerated by the modeler
lAttrib = LightAttrib.makeAllOff()
ambientLight = AmbientLight("ambientLight")
ambientLight.setColor(Vec4(.55, .55, .55, 1))
lAttrib = lAttrib.addLight(ambientLight)
directionalLight = DirectionalLight("directionalLight")
directionalLight.setDirection(Vec3(0, 0, -1))
directionalLight.setColor(Vec4(0.375, 0.375, 0.375, 1))
directionalLight.setSpecularColor(Vec4(1, 1, 1, 1))
lAttrib = lAttrib.addLight(directionalLight)
self.ballRoot.node().setAttrib(lAttrib)
#This section deals with adding a specular highlight to the ball to make
#it look shiny
m = Material()
m.setSpecular(Vec4(1, 1, 1, 1))
m.setShininess(96)
self.ball.setMaterial(m, 1)
#Finally, we call start for more initialization
self.start()
def start(self):
#The maze model also has a locator in it for where to start the ball
#To access it we use the find command
startPos = self.maze.find("**/start").getPos()
self.ballRoot.setPos(startPos) #Set the ball in the starting position
self.ballV = Vec3(0, 0, 0) #Initial velocity is 0
self.accelV = Vec3(0, 0, 0) #Initial acceleration is 0
#For a traverser to actually do collisions, you need to call
#traverser.traverse() on a part of the scene. Fortunatly, base has a
#task that does this for the entire scene once a frame. This sets up our
#traverser as the one to be called automatically
base.cTrav = self.cTrav
#Create the movement task, but first make sure it is not already running
taskMgr.remove("rollTask")
self.mainLoop = taskMgr.add(self.rollTask, "rollTask")
self.mainLoop.last = 0
#This function handles the collision between the ray and the ground
#Information about the interaction is passed in colEntry
def groundCollideHandler(self, colEntry):
#Set the ball to the appropriate Z value for it to be exactly on the ground
newZ = colEntry.getSurfacePoint(render).getZ()
self.ballRoot.setZ(newZ + .4)
#Find the acceleration direction. First the surface normal is crossed with
#the up vector to get a vector perpendicular to the slope
norm = colEntry.getSurfaceNormal(render)
accelSide = norm.cross(UP)
#Then that vector is crossed with the surface normal to get a vector that
#points down the slope. By getting the acceleration in 3D like this rather
#than in 2D, we reduce the amount of error per-frame, reducing jitter
self.accelV = norm.cross(accelSide)
#This function handles the collision between the ball and a wall
def wallCollideHandler(self, colEntry):
#First we calculate some numbers we need to do a reflection
norm = colEntry.getSurfaceNormal(render) * -1 #The normal of the wall
curSpeed = self.ballV.length() #The current speed
inVec = self.ballV / curSpeed #The direction of travel
velAngle = norm.dot(inVec) #Angle of incidance
hitDir = colEntry.getSurfacePoint(render) - self.ballRoot.getPos()
hitDir.normalize()
hitAngle = norm.dot(hitDir) #The angle between the ball and the normal
#Ignore the collision if the ball is either moving away from the wall
#already (so that we don't accidentally send it back into the wall)
#and ignore it if the collision isn't dead-on (to avoid getting caught on
#corners)
if velAngle > 0 and hitAngle > .995:
#Standard reflection equation
reflectVec = (norm * norm.dot(inVec * -1) * 2) + inVec
#This makes the velocity half of what it was if the hit was dead-on
#and nearly exactly what it was if this is a glancing blow
self.ballV = reflectVec * (curSpeed * (((1 - velAngle) * .5) + .5))
#Since we have a collision, the ball is already a little bit buried in
#the wall. This calculates a vector needed to move it so that it is
#exactly touching the wall
disp = (colEntry.getSurfacePoint(render) -
colEntry.getInteriorPoint(render))
newPos = self.ballRoot.getPos() + disp
self.ballRoot.setPos(newPos)
#This is the task that deals with making everything interactive
def rollTask(self, task):
#Standard technique for finding the amount of time since the last frame
dt = task.time - task.last
task.last = task.time
#If dt is large, then there has been a #hiccup that could cause the ball
#to leave the field if this functions runs, so ignore the frame
if dt > .2: return Task.cont
#The collision handler collects the collisions. We dispatch which function
#to handle the collision based on the name of what was collided into
for i in range(self.cHandler.getNumEntries()):
entry = self.cHandler.getEntry(i)
name = entry.getIntoNode().getName()
if name == "wall_collide": self.wallCollideHandler(entry)
elif name == "ground_collide": self.groundCollideHandler(entry)
elif name == "loseTrigger": self.loseGame(entry)
#Read the mouse position and tilt the maze accordingly
if base.mouseWatcherNode.hasMouse():
mpos = base.mouseWatcherNode.getMouse() #get the mouse position
self.maze.setP(mpos.getY() * -10)
self.maze.setR(mpos.getX() * 10)
#Finally, we move the ball
#Update the velocity based on acceleration
self.ballV += self.accelV * dt * ACCEL
#Clamp the velocity to the maximum speed
if self.ballV.lengthSquared() > MAX_SPEED_SQ:
self.ballV.normalize()
self.ballV *= MAX_SPEED
#Update the position based on the velocity
self.ballRoot.setPos(self.ballRoot.getPos() + (self.ballV * dt))
#This block of code rotates the ball. It uses something called a quaternion
#to rotate the ball around an arbitrary axis. That axis perpendicular to
#the balls rotation, and the amount has to do with the size of the ball
#This is multiplied on the previous rotation to incrimentally turn it.
prevRot = LRotationf(self.ball.getQuat())
axis = UP.cross(self.ballV)
newRot = LRotationf(axis, 45.5 * dt * self.ballV.length())
self.ball.setQuat(prevRot * newRot)
return Task.cont #Continue the task indefinitely
#If the ball hits a hole trigger, then it should fall in the hole.
#This is faked rather than dealing with the actual physics of it.
def loseGame(self, entry):
#The triggers are set up so that the center of the ball should move to the
#collision point to be in the hole
toPos = entry.getInteriorPoint(render)
taskMgr.remove('rollTask') #Stop the maze task
#Move the ball into the hole over a short sequence of time. Then wait a
#second and call start to reset the game
Sequence(
Parallel(
LerpFunc(self.ballRoot.setX,
fromData=self.ballRoot.getX(),
toData=toPos.getX(),
duration=.1),
LerpFunc(self.ballRoot.setY,
fromData=self.ballRoot.getY(),
toData=toPos.getY(),
duration=.1),
LerpFunc(self.ballRoot.setZ,
fromData=self.ballRoot.getZ(),
toData=self.ballRoot.getZ() - .9,
duration=.2)), Wait(1), Func(self.start)).start()
class World(DirectObject):
def __init__(self):
self.keyMap = {
"left": 0,
"right": 0,
"forward": 0,
"cam-left": 0,
"cam-right": 0
}
base.win.setClearColor(Vec4(0, 0, 0, 1))
# Post the instructions
self.title = addTitle(
"Panda3D Tutorial: Roaming Ralph (Walking on Uneven Terrain)")
self.inst1 = addInstructions(0.95, "[ESC]: Quit")
self.inst2 = addInstructions(0.90, "[Left Arrow]: Rotate Ralph Left")
self.inst3 = addInstructions(0.85, "[Right Arrow]: Rotate Ralph Right")
self.inst4 = addInstructions(0.80, "[Up Arrow]: Run Ralph Forward")
self.inst6 = addInstructions(0.70, "[A]: Rotate Camera Left")
self.inst7 = addInstructions(0.65, "[S]: Rotate Camera Right")
# Set up the environment
#
# This environment model contains collision meshes. If you look
# in the egg file, you will see the following:
#
# <Collide> { Polyset keep descend }
#
# This tag causes the following mesh to be converted to a collision
# mesh -- a mesh which is optimized for collision, not rendering.
# It also keeps the original mesh, so there are now two copies ---
# one optimized for rendering, one for collisions.
self.environ = loader.loadModel("models/samples/roaming_ralph/world")
self.environ.reparentTo(render)
self.environ.setPos(0, 0, 0)
# Create the main character, Ralph
ralphStartPos = self.environ.find("**/start_point").getPos()
self.ralph = Actor(
"models/samples/roaming_ralph/ralph", {
"run": "models/samples/roaming_ralph/ralph_run",
"walk": "models/samples/roaming_ralph/ralph_walk"
})
self.ralph.reparentTo(render)
self.ralph.setScale(.2)
self.ralph.setPos(ralphStartPos)
# Create a floater object. We use the "floater" as a temporary
# variable in a variety of calculations.
self.floater = NodePath(PandaNode("floater"))
self.floater.reparentTo(render)
# Accept the control keys for movement and rotation
self.accept("escape", sys.exit)
self.accept("arrow_left", self.setKey, ["left", 1])
self.accept("arrow_right", self.setKey, ["right", 1])
self.accept("arrow_up", self.setKey, ["forward", 1])
self.accept("a", self.setKey, ["cam-left", 1])
self.accept("s", self.setKey, ["cam-right", 1])
self.accept("arrow_left-up", self.setKey, ["left", 0])
self.accept("arrow_right-up", self.setKey, ["right", 0])
self.accept("arrow_up-up", self.setKey, ["forward", 0])
self.accept("a-up", self.setKey, ["cam-left", 0])
self.accept("s-up", self.setKey, ["cam-right", 0])
taskMgr.add(self.move, "moveTask")
# Game state variables
self.isMoving = False
# Set up the camera
base.disableMouse()
base.camera.setPos(self.ralph.getX(), self.ralph.getY() + 10, 2)
# We will detect the height of the terrain by creating a collision
# ray and casting it downward toward the terrain. One ray will
# start above ralph's head, and the other will start above the camera.
# A ray may hit the terrain, or it may hit a rock or a tree. If it
# hits the terrain, we can detect the height. If it hits anything
# else, we rule that the move is illegal.
self.cTrav = CollisionTraverser()
self.ralphGroundRay = CollisionRay()
self.ralphGroundRay.setOrigin(0, 0, 1000)
self.ralphGroundRay.setDirection(0, 0, -1)
self.ralphGroundCol = CollisionNode('ralphRay')
self.ralphGroundCol.addSolid(self.ralphGroundRay)
self.ralphGroundCol.setFromCollideMask(BitMask32.bit(0))
self.ralphGroundCol.setIntoCollideMask(BitMask32.allOff())
self.ralphGroundColNp = self.ralph.attachNewNode(self.ralphGroundCol)
self.ralphGroundHandler = CollisionHandlerQueue()
self.cTrav.addCollider(self.ralphGroundColNp, self.ralphGroundHandler)
self.camGroundRay = CollisionRay()
self.camGroundRay.setOrigin(0, 0, 1000)
self.camGroundRay.setDirection(0, 0, -1)
self.camGroundCol = CollisionNode('camRay')
self.camGroundCol.addSolid(self.camGroundRay)
self.camGroundCol.setFromCollideMask(BitMask32.bit(0))
self.camGroundCol.setIntoCollideMask(BitMask32.allOff())
self.camGroundColNp = base.camera.attachNewNode(self.camGroundCol)
self.camGroundHandler = CollisionHandlerQueue()
self.cTrav.addCollider(self.camGroundColNp, self.camGroundHandler)
# Uncomment this line to see the collision rays
#self.ralphGroundColNp.show()
#self.camGroundColNp.show()
#Uncomment this line to show a visual representation of the
#collisions occuring
#self.cTrav.showCollisions(render)
#Records the state of the arrow keys
def setKey(self, key, value):
self.keyMap[key] = value
# Accepts arrow keys to move either the player or the menu cursor,
# Also deals with grid checking and collision detection
def move(self, task):
# Get the time elapsed since last frame. We need this
# for framerate-independent movement.
elapsed = globalClock.getDt()
# If the camera-left key is pressed, move camera left.
# If the camera-right key is pressed, move camera right.
base.camera.lookAt(self.ralph)
if (self.keyMap["cam-left"] != 0):
base.camera.setX(base.camera, -(elapsed * 20))
if (self.keyMap["cam-right"] != 0):
base.camera.setX(base.camera, +(elapsed * 20))
# save ralph's initial position so that we can restore it,
# in case he falls off the map or runs into something.
startpos = self.ralph.getPos()
# If a move-key is pressed, move ralph in the specified direction.
if (self.keyMap["left"] != 0):
self.ralph.setH(self.ralph.getH() + elapsed * 300)
if (self.keyMap["right"] != 0):
self.ralph.setH(self.ralph.getH() - elapsed * 300)
if (self.keyMap["forward"] != 0):
self.ralph.setY(self.ralph, -(elapsed * 25))
# If ralph is moving, loop the run animation.
# If he is standing still, stop the animation.
if (self.keyMap["forward"] != 0) or (self.keyMap["left"] !=
0) or (self.keyMap["right"] != 0):
if self.isMoving is False:
self.ralph.loop("run")
self.isMoving = True
else:
if self.isMoving:
self.ralph.stop()
self.ralph.pose("walk", 5)
self.isMoving = False
# If the camera is too far from ralph, move it closer.
# If the camera is too close to ralph, move it farther.
camvec = self.ralph.getPos() - base.camera.getPos()
camvec.setZ(0)
camdist = camvec.length()
camvec.normalize()
if (camdist > 10.0):
base.camera.setPos(base.camera.getPos() + camvec * (camdist - 10))
camdist = 10.0
if (camdist < 5.0):
base.camera.setPos(base.camera.getPos() - camvec * (5 - camdist))
camdist = 5.0
# Now check for collisions.
self.cTrav.traverse(render)
# Adjust ralph's Z coordinate. If ralph's ray hit terrain,
# update his Z. If it hit anything else, or didn't hit anything, put
# him back where he was last frame.
entries = []
for i in range(self.ralphGroundHandler.getNumEntries()):
entry = self.ralphGroundHandler.getEntry(i)
entries.append(entry)
entries.sort(lambda x, y: cmp(
y.getSurfacePoint(render).getZ(),
x.getSurfacePoint(render).getZ()))
if (len(entries) > 0) and (entries[0].getIntoNode().getName()
== "terrain"):
self.ralph.setZ(entries[0].getSurfacePoint(render).getZ())
else:
self.ralph.setPos(startpos)
# Keep the camera at one foot above the terrain,
# or two feet above ralph, whichever is greater.
entries = []
for i in range(self.camGroundHandler.getNumEntries()):
entry = self.camGroundHandler.getEntry(i)
entries.append(entry)
entries.sort(lambda x, y: cmp(
y.getSurfacePoint(render).getZ(),
x.getSurfacePoint(render).getZ()))
if (len(entries) > 0) and (entries[0].getIntoNode().getName()
== "terrain"):
base.camera.setZ(entries[0].getSurfacePoint(render).getZ() + 1.0)
if (base.camera.getZ() < self.ralph.getZ() + 2.0):
base.camera.setZ(self.ralph.getZ() + 2.0)
# The camera should look in ralph's direction,
# but it should also try to stay horizontal, so look at
# a floater which hovers above ralph's head.
self.floater.setPos(self.ralph.getPos())
self.floater.setZ(self.ralph.getZ() + 2.0)
base.camera.lookAt(self.floater)
return Task.cont