from keyframe to keyframe movement (loop stop done wrong?)

Game Engine Game Engine Support and Discussion
1

I am trying to set up a basic presentation file based on this:

My problem:
How do I set up the logic to move the camera from keyframe to keyframe (autostop at keyframes, like in the vid).

Loop Stop seems to stop where it is - I want the movement to go from keyframe to keyframe when i hit a key (space or cursor keys).

prezi_style.blend (464 KB)

EDIT:
Marking as solved. Any help with scripting would be appreciated, but i’ll guess i have to get familiar with blender API anyways. if i get a version running, i’ll post it here.

2

The logic in the tutorial does not make the animation stop at key frames. The BGE does not even know you have key frames.

Loop does what it says it plays from beginning to the end and starts again.
When it receives a negative Pulse (Key release) from the sensor the actuator gets deactivated.

Loop Stop: the actuator stops on deactivation
Loop End: the actuator stops after the animation is completed

If you want to step through the positions you have following options:

States:
use states. Each state should do:

Always (no Pulses, Level enabled) --> AND --> Play (Start: End: frames of the clip to be played)
keyboard sensor -> AND -> state (next state)

Property control:
As this can be a lot of redundant work you might want to use one actuator and one state:

Properties:
float “frame” 1.000
bool “active” False
float “frameSize” 0.42

Always (no Pulses) --> AND --> Property mode (Frame: frame)
property (True Pulse) active equals True --> AND -> Property (Add prop: frame Value: frameSize)

Now you need one property sensor for each key frame in your clip:
property (no Pulses) interval frame Min: <your keyframe number> Max: 9999999
e.g.
50 - 99999
150 - 99999
210 - 99999

connect them to
–> OR -> Property (Assign Prop: active Value: False)

The advantage is you could run the animation backwards (not included in this logic). You can play it with any speed you like (see frameSize).


SimpleFCurvePlayerLogic.png895×651 85.2 KB

Python:
Keyboard (no pulses) -> Python controller -> F-Curve Actuator (play start:1 end:2)

The python code need to:

  • listen to the sensor
  • set the parameters of the actuator (according to the next clip interval)
  • activate the actuator

I hope it gives you an idea

3

Hey Thanks, monster! i viewed the tutorial a 2nd time and got it. the guy was hiding the fact a little (or overseeing that it is a real difference to what prezi does) that movement wouldn’t stop, even in the second part it was not really controllable with keyframes.

I want the file not to be redundant, and easy to set up. so it should not have a fixed amount of keyframes, nor should the thing be any more complicated than opening, importing stuff and moving+keyframing the camera and hitting p.

i guess i’ll have to look into python…

4

after a bit off fiddling around and getting behind your logic, i think i have found a pretty well solution which does not require adding bricks for each slide (waypoint) and does not need custom scripting.

Thanks for the screenshots, monster. That helped alot!

the script stops every 10 Frames (adjustable), thats it :slight_smile:

Download: poormans_prezi.blend (575 KB)