Using the Canvas "Stamp" block

Hi folks -
I’m having trouble with the Canvas’ “stamp” block. It might just be that I don’t know how it works and I’m finding only sparse documentation of it. I have a basic example here: Thunkable

And stamps do not seem to be appearing in the Canvas
What I would expect: Everytime we click on the canvas, a star shows up at the click point (the only sprite in the example is a star image).
What I get: Everytime I click, the sprite moves to the click point, but does not leave a stamped image behind.

Any ideas about what I could be doing wrong here?

1 Like

See the docs part about it here

Yea, I’ve checked out that bit of documentation, and that’s exactly what I’m expecting it to do. The problem I’m having is that it is not doing that. Or potentially I’m confused about what a “freeze frame” is, if it’s something more technical than I expect.

1 Like

Let me tell you what it means from my JavaScript knowledge. This option is used for animated sprites which will cause the sprite to stop the animation and show the current frame. Not what you would expect but this is how it is used for in JavaScript.

For the future readers of this thread:

According to the Thunkable rep I chatted with, the “stamp” block does not do what you would expect if used with a sprite that has a local image on the device. If the sprite has a url-based image, it works. This might be updated in a fix at some point.

1 Like

Can you please clarify what you mean by “what you would expect”? My understanding from this thread is that you wanted to clone a sprite but the stamp block actually freezes a sprite (animation) in place.

1 Like

I would expect the stamp block to create a static image on the canvas such that a picture of the sprite is “painted” into the stage’s drawing frame. Each stamp would produce a separate image on the drawing. These stamps would not be full clones (you could not move it, but you could draw on top of it later - because it’s just a drawing). There is actually a “stamp” block in Scratch as well, which acts this way too.

I have confirmation from the Thunkable rep that it should work this way, but it doesn’t for locally stored images. Since that conversation, I have gotten the block to work the way I’d expect by using a image for my sprite that is stored off device (the image for the sprite is a url).

3 Likes

Thanks for the explanation. That’s very helpful! Yes, I’m familiar with the stamp block in Scratch. It would be a great feature to have in Thunkable, assuming it gets fixed.

1 Like

Glad to hear that @john_shelbyhtmq !


Just to clarify @tatiang, the current functionality is currently the same as Scratch, but at the moment it doesn’t work with local assets. Using URLs, for cloud stored images works as expected though.

Will circle back next week to let you know what the situation with local assets is.

2 Likes