I saw the capture_viewport_to_buffer interface in the omni.kit.viewport.utility library, but I couldn’t find the usage instructions for this interface. I need help.
Hi @Pitt_Z. I found a good example in the omni.kit.thumbnails.mdl extension. Here’s an excerpt from the module: omni.kit.thumbnails.mdl.viewport_thumbnail_generator. Please refer to the module for the full example.
async def _capture_viewport_async(self) -> bool:
"""
Setup the viewport in the desired state and capture the viewport
Always capture to local and down sampling for better edge queality
"""
self.push_pop_renderer_settings(True)
# we are gonna resets the view so we need to wait render_iterations
for iteration in range(self._iterations):
await omni.kit.app.get_app().next_update_async()
# Capture viewport
viewport_api = get_active_viewport()
capture = capture_viewport_to_buffer(viewport_api, self.on_viewport_captured)
await omni.kit.app.get_app().next_update_async()
await capture.wait_for_result()
self.push_pop_renderer_settings(False)
return await self._is_url_exists_async(self.output_url)
def on_viewport_captured(self, buffer, buffer_size, width, height, format) -> None:
"""
Function called when capturing viewport
"""
try:
ctypes.pythonapi.PyCapsule_GetPointer.restype = ctypes.POINTER(ctypes.c_byte * buffer_size)
ctypes.pythonapi.PyCapsule_GetPointer.argtypes = [ctypes.py_object, ctypes.c_char_p]
content = ctypes.pythonapi.PyCapsule_GetPointer(buffer, None)
except Exception as e:
carb.log_error(f"[Thumbnail] Failed to get capture buffer: {e}")
return
# Crop and down sample
data = self._generate_thumbnail_data(content.contents, (width, height))
# Save to output url
result = omni.client.write_file(self.output_url, data)
if result != omni.client.Result.OK:
carb.log_error(f"[Thumbnail] Cannot write {self.output_url}, error code: {result}.")
else:
carb.log_info(f"[Thumbnail] Exported to {self.output_url}")
def _generate_thumbnail_data(self, raw_data, size: Tuple[int, int]) -> bytes:
"""
Generate desired thumbnail data from raw data
"""
# Constrcut Image object
im = Image.frombytes("RGBA", size, raw_data)
# Crop the center of the image if necessary
width, height = im.size # Get dimensions
if width != height:
if width > height:
left = (width - height) / 2
right = width - left
top = 0
bottom = height
else:
left = 0
right = width
top = (height - width) / 2
bottom = height - top
im = im.crop((left, top, right, bottom))
im.thumbnail((self._width, self._height), Image.ANTIALIAS)
# Save to buffer
buffer = io.BytesIO()
im.save(buffer, "png")
return buffer.getvalue()
If you want to know how I found this example, I show you how here: Before You Create Metaverse Apps and Tools...Watch This! - YouTube
1 Like
That’s cool. Thank you very much for sharing the method with me
How to grab SemanticSegmentation image in this buffer contents.