Realtime Compositor: Immediately realize transformations #112332

Omar Emara · 2023-09-13T16:29:55+02:00

Omar Emara commented

2023-09-13 16:29:55 +02:00

This patch immediately realizes the scale and rotation components of
transformations at the point of transform nodes. The translate component is
still delayed and only realized when really needed to avoid clipping.

Transformed results are always realized in an expanded domain that avoids
clipping due to rotation or scaling. The size of the transformed domain is
clipped to the GPU texture size limit for now until we have support for huge
textures, that limit is typically 16k.

A potential optimization is to join all consecutive transform and realize
operations into a single realize operation.

This patch immediately realizes the scale and rotation components of transformations at the point of transform nodes. The translate component is still delayed and only realized when really needed to avoid clipping. Transformed results are always realized in an expanded domain that avoids clipping due to rotation or scaling. The size of the transformed domain is clipped to the GPU texture size limit for now until we have support for huge textures, that limit is typically 16k. A potential optimization is to join all consecutive transform and realize operations into a single realize operation.

Omar Emara added 1 commit 2023-09-13 16:30:07 +02:00

9bc909b336 Realtime Compositor: Immediately realize transformations

This patch immediately realizes the scale and rotation component of
transformations at the point of transform nodes, as per the discussion
in #108944.

Omar Emara added 1 commit 2023-09-14 14:12:19 +02:00

68699e862a Realize for all transform nodes

Omar Emara added 1 commit 2023-09-14 15:07:34 +02:00

44fd9e6092 Document new algorithms

Omar Emara changed title from ~~WIP: Realtime Compositor: Immediately realize transformations~~ to Realtime Compositor: Immediately realize transformations

2023-09-14 15:09:29 +02:00

Omar Emara requested review from Sergey Sharybin 2023-09-14 15:18:07 +02:00

Omar Emara commented

2023-09-14 15:27:38 +02:00

A consequence of that change is that rotated tiles are now impossible to achieve using the Translate Wrapping mechanism.

Also, since the wrapping mode is inherited by transform nodes down the node tree, the user might not get an alpha background. But this is less of an implication of this patch and more an implication of the design of the wrapping mechanism in the compositor.

A consequence of that change is that rotated tiles are now impossible to achieve using the Translate Wrapping mechanism. <video src="/attachments/d06d7970-f17d-47ce-bcc4-37f06bbcae7e" title="20230914-162226.mp4" controls></video> Also, since the wrapping mode is inherited by transform nodes down the node tree, the user might not get an alpha background. But this is less of an implication of this patch and more an implication of the design of the wrapping mechanism in the compositor. ![20230914-162501.png](/attachments/35d4c155-be29-4efe-91eb-9cb0b15e85b1)

20230914-162501.png

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20230914-162226.mp4

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Omar Emara added 1 commit 2023-09-15 11:01:21 +02:00

buildbot/vexp-code-patch-coordinator Build done. Details

cd2214350a Fix jittered rotations

Omar Emara commented

2023-09-15 11:02:08 +02:00

@blender-bot package

Blender Bot commented

2023-09-15 11:02:12 +02:00

Package build started. Download here when ready.

Package build started. [Download here](https://builder.blender.org/download/patch/PR112332) when ready.

Sergey Sharybin commented

2023-09-19 17:33:27 +02:00

I always found wrapping a bit hard to follow because of its inheritance. Would it be possible to make it non-inheritable, applied immediately, and added to the Transform node?

Omar Emara commented

2023-09-22 13:26:58 +02:00

@Sergey It can't be applied immediately, since wrapping technically just specifies the method of realizing on a domain, "on a domain" being the keyworkd here. So that's not possible, but we always use a None wrapping method when realizing transforms if we choose to.

Sergey Sharybin commented

2023-09-22 17:43:57 +02:00

"On a domain" is the current implementation. And to me this is kind of confusing. So the idea was to not set it on a domain, and apply it immediately. So if you translate by 100px you'll immediately get an image with the translation and wrapping applied, without attempting to chain it with other nodes (and this is why we would need the option on the Transform node).

Surely, it could break some compatibility, but it does seem to simplify mental model.

"On a domain" is the current implementation. And to me this is kind of confusing. So the idea was to not set it on a domain, and apply it immediately. So if you translate by 100px you'll immediately get an image with the translation and wrapping applied, without attempting to chain it with other nodes (and this is why we would need the option on the Transform node). Surely, it could break some compatibility, but it does seem to simplify mental model.

Omar Emara commented

2023-09-25 08:22:13 +02:00

But this would remove the ability to create a repeating pattern like was possible before. Would that be acceptable?

Sergey Sharybin commented

2023-09-25 14:50:02 +02:00

I think it still would be possible if the Wrap option is added to the Transform node.

Omar Emara commented

2023-09-25 15:01:44 +02:00

If I understand correctly, immediate realization of wrapping is essentially what the Full Frame compositor already does. And it is not possible to make a repeating pattern in that case, this was described in "Section 7: Wrapping" in the comparison document, in particular, see figure 17.

fullFrameCompositorWrapping.png

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