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galleon27 wrote: Rest position is not implemented yet. Its planned for Octane 2022.x

any update on this? has it been implemented yet?

As far as I can tell, nothing has been added relating to this recently. I don't quite understand why UV coordinates can't be used for this purpose. The OP talks about "seams" caused by the use of UVs but I don't quite understand why that would be the case unless we're talking about multiple objects each with their own UV space.

toby_a wrote:As far as I can tell, nothing has been added relating to this recently. I don't quite understand why UV coordinates can't be used for this purpose. The OP talks about "seams" caused by the use of UVs but I don't quite understand why that would be the case unless we're talking about multiple objects each with their own UV space.

Hello,
because the procedural textures are sampled in uv space( 2D), you get discontinuous textures where the uvmap is discontinuous ( islands ). If it were sampled in 3D space, it would be seamless.

Goldorak wrote:For architectural and stability reasons it was my call to push Rest position and the remainder of the brigade kernel work to to the next release - 2023.1 - already well underway, see the blog post update on the home page. We will begin testing in the same slack group we used for 2021 beta.

viewtopic.php?f=24&t=80814&p=419149#p419152

Right, looks like it's not included in the 2023.1 Alpha releases at this point (it is on the list of features for later in the 2023 series).

WoutTgh wrote:

toby_a wrote:As far as I can tell, nothing has been added relating to this recently. I don't quite understand why UV coordinates can't be used for this purpose. The OP talks about "seams" caused by the use of UVs but I don't quite understand why that would be the case unless we're talking about multiple objects each with their own UV space.

Hello,
because the procedural textures are sampled in uv space( 2D), you get discontinuous textures where the uvmap is discontinuous ( islands ). If it were sampled in 3D space, it would be seamless.

Hi, thanks for the clarification. Would it work for your usecase to generate an additional UV set that doesn't have the discontinuities (for example using the UV Project Sop)? If you name the addtional UV set "uv2" and promote it to a primitive attribute then you should be able to use it in the Mesh UV Projection node in Octane as UV set 2.

toby_a wrote:

WoutTgh wrote:

toby_a wrote:As far as I can tell, nothing has been added relating to this recently. I don't quite understand why UV coordinates can't be used for this purpose. The OP talks about "seams" caused by the use of UVs but I don't quite understand why that would be the case unless we're talking about multiple objects each with their own UV space.

Hello,
because the procedural textures are sampled in uv space( 2D), you get discontinuous textures where the uvmap is discontinuous ( islands ). If it were sampled in 3D space, it would be seamless.

Hi, thanks for the clarification. Would it work for your usecase to generate an additional UV set that doesn't have the discontinuities (for example using the UV Project Sop)? If you name the addtional UV set "uv2" and promote it to a primitive attribute then you should be able to use it in the Mesh UV Projection node in Octane as UV set 2.

Hello again,

I don't see how that would work as any good uv map will always have seams. If you don't, that means you're simply flattening the mesh which means overlaps and those will of course be visible when used for texture sampling. In any case, I kinda hacked together a OSL shader ( above) that works quite well, with the exception of normal/bump mapping, something is off with that :p

WoutTgh wrote:

toby_a wrote: Hi, thanks for the clarification. Would it work for your usecase to generate an additional UV set that doesn't have the discontinuities (for example using the UV Project Sop)? If you name the addtional UV set "uv2" and promote it to a primitive attribute then you should be able to use it in the Mesh UV Projection node in Octane as UV set 2.

Hello again,

I don't see how that would work as any good uv map will always have seams. If you don't, that means you're simply flattening the mesh which means overlaps and those will of course be visible when used for texture sampling. In any case, I kinda hacked together a OSL shader ( above) that works quite well, with the exception of normal/bump mapping, something is off with that :p

OK, I don't know if I'm completely understanding this, but it sounds like it's important to have a 3D texture coordinate rather than a 2D one and I will take your word for it!

It sounds like your solution using the "rest" attribute via an OSL projection node is working well, and until Octane gets built in support for rest position is probably the best that can be done.

Are you able to create a simple scene that demonstrates the problem with normal/bump mapping?

toby_a wrote: ... sounds like it's important to have a 3D texture coordinate rather than a 2D one ...

That's exactly right

toby_a wrote: Are you able to create a simple scene that demonstrates the problem with normal/bump mapping?

I don't really have the time for this at the moment, perhaps later