Animations saved as GIF are incorrect

[PProfizi]

Before submitting the issue

• I have checked for Compatibility issues
• I have searched among the existing issues
• I am using a Python virtual environment

Description of the bug

The current code for the animator produces GIFs which are actually just the first frame repeated.

It was working in 0.12
but started failing somewhere during 0.13

Steps To Reproduce

# Import the ``ansys.dpf.core`` module
from ansys.dpf import core as dpf
# Import the examples module
from ansys.dpf.core import examples
# Import the operators module
from ansys.dpf.core import operators as ops

# Define the result file path
result_file_path = examples.find_msup_transient()
# Create the model
model = dpf.Model(data_sources=result_file_path)
# Get a scoping of all time steps available
time_steps = model.metadata.time_freq_support.time_frequencies
print(time_steps)
disp_fc = model.results.displacement(time_scoping=time_steps).eval()
print(disp_fc)
disp_fc.animate(off_screen=True, save_as="animate_disp.gif")

Whether off_screen=True or not, the generated GIF is the fist frame repeated without any changes.

Which Operating System causes the issue?

Windows

Which DPF/Ansys version are you using?

Ansys 2026 R1

Which Python version causes the issue?

3.12

Installed packages

Tested locally with:

accessible-pygments==0.0.5
alabaster==0.7.16
ansys-api-platform-instancemanagement==1.1.0
-e git+https://github.com/ansys/pydpf-core.git@901aec9a8c9d145ac2f878da6ecf8780bdafd88f#egg=ansys_dpf_core
-e git+https://github.com/ansys-dpf/dpf-standalone.git@8481cccca2e6257c2d92774de9417d9b1b002bd5#egg=ansys_dpf_server_2026_1_pre0
ansys-platform-instancemanagement==1.1.2
ansys-sphinx-theme==1.3.1
anyio==4.9.0
apeye==1.4.1
apeye-core==1.1.5
argon2-cffi==23.1.0
argon2-cffi-bindings==21.2.0
arrow==1.3.0
astroid==3.3.8
asttokens==2.4.1
async-lru==2.0.5
attrs==24.2.0
autodocsumm==0.2.14
babel==2.16.0
beautifulsoup4==4.12.3
black==24.10.0
bleach==6.2.0
build==1.2.2.post1
CacheControl==0.14.1
cachetools==5.5.0
certifi==2024.8.30
cffi==1.17.1
cfgv==3.4.0
chardet==5.2.0
charset-normalizer==3.4.0
chevron==0.14.0
click==8.1.8
colorama==0.4.6
comm==0.2.2
contourpy==1.3.1
coverage==7.6.4
cssutils==2.11.1
cycler==0.12.1
debugpy==1.8.8
decorator==5.1.1
defusedxml==0.7.1
dict2css==0.3.0.post1
distlib==0.3.9
docutils==0.20.1
domdf-python-tools==3.9.0
enum-tools==0.12.0
executing==2.1.0
fastjsonschema==2.20.0
filelock==3.16.1
fonttools==4.55.0
fqdn==1.5.1
google-api-core==2.23.0
google-auth==2.36.0
google-auth-httplib2==0.2.0
googleapis-common-protos==1.66.0
graphviz==0.20.1
grpcio==1.67.1
h11==0.16.0
html5lib==1.1
httpcore==1.0.9
httplib2==0.22.0
httpx==0.28.1
identify==2.6.2
idna==3.10
imageio==2.28.0
imageio-ffmpeg==0.5.1
imagesize==1.4.1
importlib_metadata==8.5.0
iniconfig==2.0.0
ipykernel==6.29.5
ipython==8.29.0
ipywidgets==8.1.5
isoduration==20.11.0
jedi==0.19.2
Jinja2==3.1.4
json5==0.12.0
jsonpointer==3.0.0
jsonschema==4.23.0
jsonschema-specifications==2024.10.1
jupyter-events==0.12.0
jupyter-lsp==2.2.5
jupyter-sphinx==0.5.3
jupyter_client==8.6.3
jupyter_core==5.7.2
jupyter_server==2.16.0
jupyter_server_terminals==0.5.3
jupyterlab==4.4.2
jupyterlab_pygments==0.3.0
jupyterlab_server==2.27.3
jupyterlab_widgets==3.0.13
kiwisolver==1.4.7
MarkupSafe==3.0.2
matplotlib==3.9.2
matplotlib-inline==0.1.7
mistune==3.0.2
more-itertools==10.5.0
msgpack==1.1.0
mypy-extensions==1.0.0
natsort==8.4.0
nbclient==0.10.0
nbconvert==7.16.4
nbformat==5.10.4
nbsphinx==0.9.6
nest-asyncio==1.6.0
nodeenv==1.9.1
notebook==7.4.2
notebook_shim==0.2.4
numpy==2.1.3
overrides==7.7.0
packaging==24.2
pandocfilters==1.5.1
parso==0.8.4
pathspec==0.12.1
pdf2image==1.17.0
pillow==11.0.0
platformdirs==4.3.6
pluggy==1.5.0
pockets==0.9.1
pooch==1.8.2
pre_commit==4.0.1
prometheus_client==0.21.1
prompt_toolkit==3.0.48
proto-plus==1.25.0
protobuf==5.28.3
psutil==6.1.0
pure_eval==0.2.3
pyasn1==0.6.1
pyasn1_modules==0.4.1
pycparser==2.22
pydata-sphinx-theme==0.15.4
Pygments==2.18.0
pypandoc==1.14
pypandoc_binary==1.15
pyparsing==3.2.0
pyproject-api==1.9.0
pyproject_hooks==1.2.0
pytest==8.3.3
pytest-cov==5.0.0
pytest-order==1.3.0
pytest-rerunfailures==14.0
pytest-sphinx==0.6.3
python-dateutil==2.9.0.post0
python-json-logger==3.3.0
pyvista==0.44.2
pywin32==308
pywinpty==2.0.15
PyYAML==6.0.2
pyzmq==26.2.0
referencing==0.35.1
requests==2.32.3
rfc3339-validator==0.1.4
rfc3986-validator==0.1.1
rpds-py==0.21.0
rsa==4.9
ruamel.yaml==0.18.6
ruamel.yaml.clib==0.2.12
scooby==0.10.0
Send2Trash==1.8.3
setuptools==75.5.0
six==1.16.0
sniffio==1.3.1
snowballstemmer==2.2.0
soupsieve==2.6
Sphinx==7.4.7
sphinx-autoapi==3.4.0
sphinx-autodoc-typehints==1.24.0
sphinx-copybutton==0.5.2
sphinx-gallery==0.18.0
sphinx-jinja==2.0.2
sphinx-jinja2-compat==0.3.0
sphinx-notfound-page==1.1.0
sphinx-prompt==1.8.0
sphinx-reredirects==0.1.3
sphinx-tabs==3.4.5
sphinx-toolbox==3.8.1
sphinx_design==0.6.1
sphinxcontrib-applehelp==2.0.0
sphinxcontrib-devhelp==2.0.0
sphinxcontrib-htmlhelp==2.1.0
sphinxcontrib-jsmath==1.0.1
sphinxcontrib-napoleon==0.7
sphinxcontrib-qthelp==2.0.0
sphinxcontrib-serializinghtml==2.0.0
stack-data==0.6.3
tabulate==0.9.0
terminado==0.18.1
tinycss2==1.4.0
tornado==6.4.1
tox==4.24.1
tox-uv==1.25.0
tqdm==4.67.0
traitlets==5.14.3
types-python-dateutil==2.9.0.20250516
typing_extensions==4.12.2
uri-template==1.3.0
uritemplate==4.1.1
urllib3==2.2.3
uv==0.7.3
virtualenv==20.27.1
vtk==9.3.1
wcwidth==0.2.13
webcolors==24.11.1
webencodings==0.5.1
websocket-client==1.8.0
wheel==0.45.1
widgetsnbextension==4.0.13
zipp==3.21.0

[PProfizi]

First investigation:

The animator properly sends a new field to the PyVista plotter corresponding to the new frame number.
The issue must be somewhere during the call to write_frame().

[PProfizi]

Update:

When trying to run the PyVista example, the GIF generated is also a static image.

https://docs.pyvista.org/examples/02-plot/gif.html

from __future__ import annotations

import numpy as np

import pyvista as pv

x = np.arange(-10, 10, 0.5)
y = np.arange(-10, 10, 0.5)
x, y = np.meshgrid(x, y)
r = np.sqrt(x**2 + y**2)
z = np.sin(r)

# Create and structured surface
grid = pv.StructuredGrid(x, y, z)
grid['Height'] = z.ravel()
# grid.plot()

# Create a plotter object and set the scalars to the Z height
plotter = pv.Plotter(notebook=False, off_screen=True)
plotter.add_mesh(
    grid,
    scalars='Height',
    lighting=False,
    show_edges=True,
    clim=[-1, 1],
)

# Open a gif
plotter.open_gif('wave.gif')

# Update Z and write a frame for each updated position
nframe = 15
for phase in np.linspace(0, 2 * np.pi, nframe + 1)[:nframe]:
    z = np.sin(r + phase)
    # Update values inplace
    grid.points[:, -1] = z.ravel()
    grid['Height'] = z.ravel()
    # Write a frame. This triggers a render.
    plotter.write_frame()

# Closes and finalizes movie
plotter.close()