Cant save animation in 5.13

ParaView Support
1

Hi,

I tried to export an animation about the camera moving around a 3D object, but it didn’t work.
My object was a 3D .mph data export from Matlab, and I used a Python script to define an interpolated path for the camera.
The animation worked well when I played it in Paraview, but when I tried to export it, only the first frame was saved into the .avi/.mp4 file, and no error information was given.
I can’t find any explanation or solution to this issue. Can you help me with this problem?

Thanks,
FOX

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Below is my Python script to define the camera:

from paraview.simple import *
import math

Get the current active view and camera

view = GetActiveView()
camera = view.GetActiveCamera()

Get current camera parameters

start_position = camera.GetPosition()
start_focal_point = camera.GetFocalPoint()
start_view_up = camera.GetViewUp()

Define rotation parameters

axis = [0, 0, 1] # Rotation axis, e.g., [0, 0, 1] means rotating around the Z-axis
angle_degrees = 360 # Total rotation angle in degrees
num_steps = 30 # Number of keyframes
direction = 1 # Rotation direction: 1 for positive, -1 for negative

Compute rotation center (rotate around the focal point)

center = start_focal_point

Prepare to create the keyframe list

keyframes =

for i in range(num_steps + 1):
# Calculate the current keyframe’s time and angle
key_time = i / num_steps # Keyframe time, uniformly distributed from 0 to 1
angle = math.radians(direction * angle_degrees * key_time)

# Compute rotation matrix
c = math.cos(angle)
s = math.sin(angle)
t = 1 - c
x, y, z = axis
# Normalize the rotation axis
norm = math.sqrt(x*x + y*y + z*z)
x /= norm
y /= norm
z /= norm
# Rotation matrix elements
R = [
    [t*x*x + c,     t*x*y - s*z, t*x*z + s*y],
    [t*x*y + s*z, t*y*y + c,     t*y*z - s*x],
    [t*x*z - s*y, t*y*z + s*x, t*z*z + c]
]

# Compute new camera position
p = [start_position[j] - center[j] for j in range(3)]  # Translate to origin
p_rotated = [
    R[0][0]*p[0] + R[0][1]*p[1] + R[0][2]*p[2],
    R[1][0]*p[0] + R[1][1]*p[1] + R[1][2]*p[2],
    R[2][0]*p[0] + R[2][1]*p[1] + R[2][2]*p[2]
]
new_position = [p_rotated[j] + center[j] for j in range(3)]  # Translate back to original position

# Compute new ViewUp direction
vu = start_view_up
vu_rotated = [
    R[0][0]*vu[0] + R[0][1]*vu[1] + R[0][2]*vu[2],
    R[1][0]*vu[0] + R[1][1]*vu[1] + R[1][2]*vu[2],
    R[2][0]*vu[0] + R[2][1]*vu[1] + R[2][2]*vu[2]
]

# Create keyframe
keyframe = CameraKeyFrame()
keyframe.KeyTime = key_time          # Set keyframe time
keyframe.Position = new_position     # Set camera position
keyframe.FocalPoint = start_focal_point  # Keep focal point unchanged
keyframe.ViewUp = vu_rotated         # Update ViewUp direction
keyframes.append(keyframe)

Set up animation scene

animationScene = GetAnimationScene()
animationScene.StartTime = 0
animationScene.EndTime = 1 # Use normalized time (0 to 1)
animationScene.PlayMode = ‘Sequence’ # Ensure play mode is ‘Sequence’
animationScene.NumberOfFrames = num_steps # Set number of frames

Create camera animation track and assign keyframes

cameraAnimationCue = GetCameraTrack(view)
cameraAnimationCue.KeyFrames = keyframes

Optional: Play animation or save animation

animationScene.Play()

2

Hi @FOX_HU

In 5.13 the default frame range is not great, you have to specify it yourself.

In the save animation dialog, show advanced option (the “cogwheel”) and then change the frame maximum range to 100

hth

3

Thanks, Mathieu!
Problem solved now :slight_smile:

FOX