bitmap output

[oroszl]

Is there a way for producing a bitmap image of the rendnering ? Looking at some threejs examples I found that from threejs it is in principle possible to produce a png output, but if I am not mistaken pythreejs is not yet setup to do so.

[jasongrout]

Yep, there are ways to do it, but we are not set up to do it yet. We'll keep this issue open as a todo item.

[oroszl]

Thanks..

[oroszl]

from this post
http://stackoverflow.com/questions/15558418/how-do-you-save-an-image-from-a-three-js-canvas
it seems that if one uses the canvas renderer threejs would be able to generate a dataurl.
is it hard to bubble it up to pythreejs ?

[jasongrout]

no, not hard at all. Or we can do it with the webgl renderer, as in the first answer.

[jasongrout]

This also looks interesting: http://stackoverflow.com/a/22579139

[oroszl]

I was also wondering if it is possible to use ipython it self maybe trough some trickery with display() ?

[arizhakov]

Has there been any updates on this issue (e.g., concrete pythreejs implementation of three.js capability to produce image data output), or are the above links the only leads to play with at the moment?

[MannyKayy]

Bumping this issue

[maartenbreddels]

In ipyvolume I do screenshots by indeed saving the canvas to a png, and sending that over the wire. I think a good way so solve this issue (and #167) is to make the renderer an (ipywebrtc) MediaStream, and put this feature in ipywebrtc. The video part is already working, I think it's not so difficult to add what is done on the backend and frontend to ipywebrtc (frontend and backend)

Pythreejs's renderer needs to inherit from from MediaStream (backend) and deliver a mediastream (for the first view) on the frontend.
If someone wants to take a shot, I'm happy to help.

[elPistolero]

With help from the code (backend and frontend) I implemented a first working version.

I haven't figured out how to directly return the image data from the RenderableWidget screenshot method yet.

[maartenbreddels]

There is a gory way of doing that, if you start diving into this part which ends up doing a busy loop
If you find a better way, let me know.
In any case, I think this should all move into ipywebrtc/jupyter-webrtc

[elPistolero]

I saw the busy loop, but I was wondering whether it would be possible for the screenshot function itself to internally wait until the data is ready and then return the image.
So something like:

def screenshot(self):
        self.screenshot_ready = False
        content = {
            "type": "screenshot"
        }
        self.send(content)
        busy_loop()
        return self.screenshot_data

However, when I tried this the returned data seems to be gobbled up.
Does this have something to do with the fact that RenderableWidget is a DOMWidget?

Is moving this into ipywebrtc/jupyter-webrtc and introducing a new dependency for pythreejs something the maintainers of this project want?