Photoshop to Spine script - add rotation

Hocopor

Hi! Can you add tag [rotate:degrees] for script to optimize sprites for atlas.
For example, if I specify [rotate:-30], Photoshop automatically rotates the sprite by -30 degrees when saving, and when importing into json, it rotates it by 30 degrees so that it ends up in the right place.

Thank you!

Spinebot

I understand you'd like a [rotate:degrees] tag in the PhotoshopToSpine script to help optimize sprites for atlas packing by pre-rotating them.

This is an interesting idea for optimization! However, implementing rotation in the PhotoshopToSpine script would be quite complex for a few reasons:

Technical challenges:

Photoshop scripting limitations - Photoshop's scripting capabilities are relatively poor and finding optimal rotations would be very slow to execute in the script itself.
UV coordinate adjustments - When images are rotated at arbitrary angles (other than 0, 90, 180, 270 degrees), Spine would need to adjust mesh UVs to work correctly with the rotated images. This is complex to implement.
Image quality concerns - Rotations other than 90-degree increments require pixel interpolation/filtering, which can affect image quality since the pixels no longer align with the output image grid.

Better alternatives:

Spine's texture packer already includes polygon packing with automatic rotation at 0, 90, 180, and 270 degrees. These rotations preserve image quality while optimizing atlas space. You might want to explore this feature first to see if it meets your needs.

If you specifically need custom angle rotations for optimization, this would be better suited as a separate tool that runs after the Photoshop script exports but before importing into Spine - it would rotate the images and update the JSON accordingly.

Hocopor

I'm talking about rotating the sprite manually, not using an algorithm. I rotate the sprite myself to the value I need, then specify the rotation value in the tag, and when creating the JSON, Spine takes the tag into account and rotates the sprite in the desired direction automatically. It's similar to [scale:], except that the sprite is rotated manually, and the reverse rotation is done automatically.

Davide

Hocopor

As far as I understand, the rotation would be applied to the exported PNG and the attachment in the JSON. This would result in no visible rotation, so the name is not thet intuitive.
The usage of the [rotate] tag you proposed also makes it quite difficult to achieve optimizations
(for each layer I manually need to add a tag with the rotation I applied).

As Spinebot said, polygon packing works pretty well.
I'll discuss this internally and let you know.

Hocopor

Let's say I rotate the sprite by -30 degrees, write [rotate:-30], and Spine automatically adds a value of 30 in the opposite direction to the rotation to restore the original rotation of the sprite.

Hocopor

Rotation add manually in photoshop. I've already rotated the sprite myself as needed. The tag simply rotates it in the spine to the desired degree. A polygonal atlas doesn't always help. There are specific shaders, for example, where UV coordinates are used and sprites must be rectangular rather than polygonal.

Davide

Hocopor

So, you want to end up with something that is visually different from Photoshop?

For example, if I just have a square in Photoshop that is not rotated, and I add the tag [rotate:45], you expect:

the PNG attachment to look the same as in Photoshop
the attachment in the JSON to have -45°

So, in Spine you will see the square rotated by -45°?

Hocopor

Yes, that's right. A sprite from Photoshop is exported exactly as it appears there. That is, no manipulation is required. You just need to add a tag (it is also advisable to combine it with the scale tag if it is a rotated and scaled texture). And in Spine, the sprite is already displayed rotated by the specified degree and scaled if specified by the tag.

Davide

Hocopor

We could do that, but it’s not clear to me how this would optimize sprites for the atlas.
Could you show us a complete example of your goal and explain how it would “optimize sprites for the atlas”?

We’re always open to implementing feature requests, but we need to clearly understand their goals, and right now that isn’t very clear, unfortunately 🙁

Hocopor

https://disk.yandex.ru/i/9R10Qz93jPgM1w

Davide

Hocopor

Thanks for the illustration. The intentions are now pretty clear.
We’ll discuss it internally and let you know if we’re willing to implement it.

Hocopor

Thanks!)

Davide

Hocopor

We'll probably implement it, but with a slightly different behavior. [rotate:degrees] will behave similarly to the [scale:value] tag.

The image will be exported rotated by degrees, and the corresponding attachment in the JSON will be rotated by -degrees.

This will allow keeping the image visually coherent in Photoshop and Spine, while allowing the actual PNG to be rotated as desired to easily pack it in the atlas.

Hocopor

Thank you! This will be a very useful addition to the script!

Hocopor

Hi! Is there any progress?

Davide

Hocopor

Sorry for the delay. As any new feature, it will available only in the next beta.
Even if it's still in validation, we actually implemented it as described above.

Hocopor

Thank you!

Davide

Hocopor

4.3.40-beta is out and you can now test the new rotation tag.
User guide was updated accordingly: https://esotericsoftware.com/spine-import-psd#Group-and-layer-tags

[rotate:degrees] Layers are rotated. Their attachments are rotated inversely so that they appear the same in Spine. This is useful to rotate images for better atlas packing.

warmanw

Hey Davide,

I tried this tag but it does not trim before export and image size remains document size

Davide

warmanw

Fixed as reported in this thread.