Here’s a runnable piece of test code http://caslav.gmxhome.de/misc/perf02.zip which draws a somewhat irregular rotating spiral, composed of small spheres. The spheres shrink and fade out as they move outwards, until they dissapear. At given settings (SpiralBlobber instantiation), there are about 1000 spheres in the spiral at any time on the screen. Here’s the task that updates the spiral (which is most of the code in the perf02.py in the archive):
def loop (self, task):
if not self.alive:
return task.done
dt = task.time - task.prev_time
task.prev_time = task.time
self._update_spiral(dt)
return task.cont
def _update_spiral (self, dt):
# Remove expired blobs.
mod_blobs = []
for node, age, drift in self._blobs:
if age < self._duration:
mod_blobs.append((node, age, drift))
else:
node.removeNode()
self._blobs = mod_blobs
# Create new blobs to replace expired.
self._time_to_next -= dt
while self._time_to_next <= 0.0:
node = self._model.copyTo(self._topnode)
node.setScale(self._scale1)
age = -self._time_to_next - dt
drift = random.uniform(-0.05, 0.05)
self._update_pos(node, age, drift)
self._blobs.append((node, age, drift))
self._time_to_next += self._period
#print len(self._blobs)
# Move blobs.
mod_blobs = []
for node, age, drift in self._blobs:
age += dt
agefrac = age / self._duration
node.setAlphaScale(1.0 - agefrac)
scale = self._scale1 + agefrac * (self._scale2 - self._scale1)
node.setScale(scale)
self._update_pos(node, age, drift)
mod_blobs.append((node, age, drift))
self._blobs = mod_blobs
def _update_pos (self, node, age, drift):
radspeed = self._radspeed * (1 + drift)
tanspeed = self._tanspeed * (1 + drift)
rad = radspeed * age
if rad < self._initrad:
ang = 0.0
else:
age0 = self._initrad / self._radspeed
ang = (tanspeed / radspeed) * math.log(age / age0)
node.setPos(rad * math.cos(ang), 0.0, rad * math.sin(ang))On an i7 at 3.33 GHz and Radeon 5870, I get about 25 fps with this code. Here’s also the screenshot from pstats:
I wonder if performance could be improved somehow? (I have no prior experience at 3D programming.)
I’ve read the performance tuning section in the manual, but could not speed the code up. E.g. if I remove the two state changes on each sphere (node.setAlphaScale(…) and node.setScale(…)), indeed the time in pstats “App” section drops by about factor two, but that also changes the result. Or, each default sphere is 80 polygons (“sphere80” in the code), and if I use a sphere with 1280 polygons (“sphere1280”, also in the linked archive) indeed I get no further performance decrease, so I guess the problem is in (high?) number of models in the scene rather than total number of polygons.