Hey fellows, I’ve managed to draw lines using the mouse in the direction of plane xy,xz,yz with angular steps. However, when I try to move the origin of the line in the using the yz plane the visual aid (a circle and a line) rotates wrongly. Any ideas why this happens? Here follows my code and images regarding the issue. This only happens when I change to rotate the line around y-axis.
import math
from panda3d.core import *
from direct.showbase.ShowBase import ShowBase
from direct.gui.OnscreenText import OnscreenText
# Function to put instructions on the screen.
def addInstructions(pos, msg):
return OnscreenText(text=msg, style=1, fg=(1, 1, 1, 1), scale=.05,
shadow=(0, 0, 0, 1), parent=base.a2dTopLeft,
pos=(0.08, -pos - 0.04), align=TextNode.ALeft)
class MyApp(ShowBase):
def __init__(self):
ShowBase.__init__(self)
#disable mouse, we need the left click working
base.disableMouse()
#set sensible view
base.cam.set_pos(20, -20, 20)
base.cam.look_at(0,0,0)
#help info
self.inst1 = addInstructions(0.06, "MOUSE-LEFT: click and hold / MOUSE RIGHT : Draw line")
self.inst2 = addInstructions(0.12, "X, Y, Z: change rotation axis")
self.inst3 = addInstructions(0.18, "Vector")
self.inst4 = addInstructions(0.24, "Last vector")
self.inst5 = addInstructions(0.30, "Position")
#origin
self.origin = Point3(0,0,0)
#visual aid
self.circle=self.make_circle()
#mouse left or right click control
self.mouse_left_is_down = False
self.mouse_right_is_down = False
#temporary line between the mouse and the origin
self.aux_line = None
#the line you want to draw
self.last_line = None
#a line showing the current rotation axis
self.line=None
#the axis node, we rotate around this node
self.axis=render.attach_new_node('axis')
#list of current axis, overkill here, but used for moving
self.active_axis='z'
self.update_axis(Point3(0,0,0))
self.mouse_is_down=False
#bind keys
self.accept('mouse1', self.on_mouse_left_down)
self.accept('mouse1-up', self.on_mouse_left_up)
self.accept('mouse3', self.on_mouse_right_down)
self.accept('mouse3-up', self.on_mouse_right_up)
self.accept('x', self.toggle_axis, ['x'])
self.accept('y', self.toggle_axis, ['y'])
self.accept('z', self.toggle_axis, ['z'])
#run task
taskMgr.add(self.mouse_task, 'mouse_tsk')
def make_circle(self, segments = 360, thickness=2.0, radius=2.0):
l=LineSegs()
l.set_thickness(thickness)
l.move_to(self.origin)
l.draw_to((0, radius, 0))
temp = NodePath('temp')
for i in range(segments + 1):
temp.set_h(i * 360.0 / segments)
p = render.get_relative_point(temp, (0, radius/2, 0))
l.draw_to(p)
temp.remove_node()
return render.attach_new_node(l.create())
def draw_node(self, position):
sphere = loader.loadModel("misc/sphere.egg")
sphere.reparentTo(render)
sphere.setScale(0.1)
sphere.setPos(position)
sphere.setColor(0, 0, 0)
return sphere
def on_mouse_left_down(self):
self.mouse_left_is_down = True
print('mouse left down')
def on_mouse_right_down(self):
self.mouse_right_is_down = True
print('mouse right down')
self.last_vec = None
self.mouse_is_down = True
def on_mouse_left_up(self):
self.mouse_left_is_down = False
print('mouse left up')
def on_mouse_right_up(self):
self.mouse_right_is_down = False
print('mouse right up')
self.inst4.setText(str(self.last_vec))
l = LineSegs()
self.draw_node(self.last_line[0])
l.move_to(self.last_line[0])
self.draw_node(self.last_line[1])
l.draw_to(self.last_line[1])
render.attach_new_node(l.create())
def toggle_axis(self, axis):
self.active_axis = axis
self.update_axis(self.origin)
def update_axis(self, point):
'''Creates a plane to capture mouse clicks,
the pos of self.axis defines the point for the plane,
the normal of the plane depends on what is
the current axis in self.active_axis.
Also draws a line/vector to show the axis.
'''
if 'x' in self.active_axis:
vec=self.axis.get_quat().get_right()
elif 'y' in self.active_axis:
vec=self.axis.get_quat().get_forward()
elif 'z' in self.active_axis:
vec=self.axis.get_quat().get_up()
#remove old line
if self.line:
self.line.remove_node()
#draw new line
if self.active_axis:
self.plane=Plane(vec, point) # also make the plane, kind of important...
l=LineSegs()
l.set_thickness(2.0)
l.move_to(point)
l.draw_to((point+vec))
self.line=render.attach_new_node(l.create())
self.line.set_color((abs(vec.x), abs(vec.y), abs(vec.z), 1.0), 1)
self.circle.set_color(self.line.get_color(), 1) #recolor the circle to make it fit
def mouse_task(self, task):
'''Rotates self.model around self.axis based on mouse movement '''
if self.active_axis:
if base.mouseWatcherNode.has_mouse():
# get the mouse ray-plane intersection
mpos = base.mouseWatcherNode.get_mouse()
pos3d = Point3()
near_point = Point3()
far_point = Point3()
base.camLens.extrude(mpos, near_point, far_point)
if self.plane.intersects_line(pos3d,
render.get_relative_point(base.cam, near_point),
render.get_relative_point(base.cam, far_point)):
self.inst5.setText(str(pos3d))
if self.mouse_left_is_down:
self.update_axis(pos3d)
self.origin = pos3d
self.circle.set_pos(self.origin)
vec = pos3d - self.axis.get_pos()
angle_vector = pos3d - self.origin
# calculate the angle
angle = 0
if self.active_axis == 'x':
angle = math.atan2(angle_vector.y, angle_vector.z)
if self.active_axis == 'y':
angle = math.atan2(angle_vector.x, angle_vector.z)
if self.active_axis == 'z':
angle = math.atan2(angle_vector.x, angle_vector.y)
angle_in_degrees = round(math.degrees(angle))
if angle_in_degrees % 5 == 0:
if angle_in_degrees < 0:
angle_in_degrees += 360
self.inst3.setText(str(angle_in_degrees))
self.circle.look_at(pos3d, self.plane.get_normal())
self.circle.show()
# remove if exists previous auxiliar line
if self.aux_line : self.aux_line.removeAllGeoms()
#draw the auxiliar line
l = LineSegs()
l.move_to(self.circle.get_pos())
l.draw_to(vec)
#store the auxiliar line
self.aux_line = l.create()
render.attach_new_node(self.aux_line)
self.last_line = (self.circle.get_pos(),vec)
return task.again
app = MyApp()
app.run()
Wrong movement
Right after a change in angle
