View Full Version : What does this job requirement mean exactly?


Pinoy McGee
12 December 2008, 06:33 AM
Upstream & downstream understanding of texturing (UVs)

Upstream and downstream refers to what.

Swizzle
12 December 2008, 07:21 AM
At first glance it reminds me of marketing speak.

JamesMK
12 December 2008, 07:39 AM
At first glance it reminds me of marketing speak.
It does indeed.

However, it could be interpreted in a way that makes some sense as well, looking at the flow from Modeling -> UVs -> Texturing in which the UVs obviously sit in the middle - meaning that UV "upstream" is the way the model topology puts certain constraints on the UV layout, whereas UV "downstream" is the way the UV layout in turn obviously affects the texture painting.

Sounds fuzzy, but of course it makes sense in a pipeline kinda way.

R10k
12 December 2008, 09:08 AM
Interesting. The only other stream they're missing of course is- extreme.

mister3d
12 December 2008, 09:17 AM
This is obviously done to sift out people who they don't like. "Ahh, you even don't know what is downstream and upstream texturing is...go away!"

leigh
12 December 2008, 10:08 AM
I am assuming it means that you have a knowledge of the processes that go on before and after the texturing stage, which is actually a good skill for someone who does textures.

Pinoy McGee
12 December 2008, 11:50 AM
and after the texturing stage, which is actually a good skill for someone who does textures.

Processes after the texturing stage would be? :)

No, really Leigh. I don't know what that constitutes. Would that be just tweaking or colour correcting the textures or mattes?

Equinoxx
12 December 2008, 11:55 AM
that would probably be lighting, e.g. the way the texture(material) reacts to light

ThomasMahler
12 December 2008, 11:59 AM
Yeah, they probably just expect you to know how and why you texture a model and what happens before and after the texturing stage in the pipeline (including doing UV Layouts), like probably baking and / or baking procedurals and stuff.

leigh
12 December 2008, 12:00 PM
that would probably be lighting, e.g. the way the texture(material) reacts to light

Bingo. Lighting and shading is the next step in the pipeline, and being able to communicate well with the lookdev TD's is a necessary skill. Remember, texture painters, especially in VFX, do a lot more than just colour, bump and spec maps - we work together with lookdev, creating all kinds of odd custom ID maps and such to help with the lookdev process, and if you're able to understand a bit about the lookdev process, then that's going to help with this.

People who work in a pipeline without knowing what the people next in line are going to be doing often cause problems.

mister3d
12 December 2008, 12:01 PM
Processes after the texturing stage would be? :)



At least how specular and bump maps are used, etc, texture stretching, resolution.

Leigh, could you tell a bit about lookdev please? What is it?

Pinoy McGee
12 December 2008, 12:05 PM
Laying out the shader tree too, eh.

Thanks guys. Just wondering if there was something industry specific there that I wasn't aware of.

leigh
12 December 2008, 12:43 PM
Leigh, could you tell a bit about lookdev please? What is it?

Lookdev = look development. It's basically the stage where the textures are taken and the shaders are created and set up. A lookdev TD is in charge of setting up the surfaces for the objects before sending them to lighting.

mister3d
12 December 2008, 12:48 PM
Lookdev = look development. It's basically the stage where the textures are taken and the shaders are created and set up. A lookdev TD is in charge of setting up the surfaces for the objects before sending them to lighting.

Thank you for the reply. Wow, that's cool! But I guess lighters tweak the shaders yet after that stage.

ThE_JacO
12 December 2008, 01:04 PM
Thank you for the reply. Wow, that's cool! But I guess lighters tweak the shaders yet after that stage.
Not if it can be avoided! :p

But more seriously:
Depends from the shop, the amount of people on the floor, the pipeline, and what stage things are at.

The definition of LookDev is also something that changes slightly depending on where you work.
In some places it covers things from RnD to compiling and it relies on a feedback loop, in some others it's in the hand of less technical people (or technically minded artists), and then it's cleaned, refactored and polished for assembly afterwards, redelivered and frozen as much as possible.

The shading process itself is something that can change wildly from place to place.
In some shops AOVs for something like characters are spat out only for precomp to contribute to look-dev, once that gets anywhere meaningful and wedges (variations) on some key parameters are created the pre-comp is retransmitted to the shader itself and AOVs get culled or output on demand only, leaving comp to work with actual comp shots and treating CG contributions monolithically.

In some other places the granularity of the output stays high all the way through and re-assembly is left to comp pulling together a ridiculous amount of passes, or running a precomp of the elements first.

As a texture artist knowledge of entry and exit points in the pipe of your work and how it affects things downstream, and knowing what you are being handed and what to ask for from upstream, is invaluable.
Some knowledge of colour spaces and all the correlated furniture is also nice if you work in film, but given that 9 lighting artists out of 10 couldn't light their way out of a sunpatch when it comes to that means just respect of some colour guidelines and procedures (being able to parrot corrections or equalisation tools on and off at the right time) is often considered enough (tolerated) in texture artist roles, even if it's not ideal.

P.S.
And no, downstream and upstream are not marketing words. They are in common use and growing in adoption in most things dealing with process or data flow :)
It can also be taken quite literally and it will make sense.

mister3d
12 December 2008, 02:23 PM
I'm not familiar with those cool big pipelines, so this stage is a surprise for me. I thought lighters adjust the shaders and rely solely on artistic llcence, ha-ha. I also thought lighters tweak the textures to make the final renders. Ok, I understand the shaders are adjusted as close as possible to realworld values, but how they get tested without lighting? How can you know that this will look ok if not tested with the actual lighting?
I can only imagine some 360 degrees turnaround test renders, but still, in relation to what environment?

AJ
12 December 2008, 02:33 PM
In some shops AOVs for something like characters are spat out only for precomp to contribute to look-dev, once that gets anywhere meaningful and wedges (variations) on some key parameters are created the pre-comp is retransmitted to the shader itself and AOVs get culled or output on demand only, leaving comp to work with actual comp shots and treating CG contributions monolithically.

In some other places the granularity of the output stays high all the way through and re-assembly is left to comp pulling together a ridiculous amount of passes, or running a precomp of the elements first.
That is an impressively impenetrabile explanation.

ThE_JacO
12 December 2008, 02:40 PM
Does the addition of this:
AOV = Arbitrary Output Variables, aka RMan equivalent to MRay channels, aka multiple outputs from a shader(s) from the same rendering
Make things any clearer?

It's kinda tough to talk about shading and/or output pipelines without writing several pages and engaging into painful debates with other pipeline engineers that suddenly will pop up and start arguing the merits and faults of every detail.
I probably shouldn't have tried in first place :p

AJ
12 December 2008, 02:49 PM
Sorry, I do appreciate what you were saying - it was just phrased in such a way that made my brain cry.

:)

ThE_JacO
12 December 2008, 02:53 PM
Re-reading I have to admit it sounds pretty ****ing obscure unless you can relate to most of what I was talking about, in which case you probably wouldn't get anything from reading it anyway.
On the upside: People can always ask about the details to move the thread forward, or just jot down a note and make sure to hurl it the way of a producer at the next pipeline meeting. It's the kind of stuff that can shut down an entire studio of them for a whole day.

mister3d
12 December 2008, 03:00 PM
On the upside: People can always ask about the details to move the thread forward, or just jot down a note and make sure to hurl it the way of a producer at the next pipeline meeting. It's the kind of stuff that can shut down an entire studio of them for a whole day.
:D Brilliant!
Actually I think I got what you mean there: making fast adjustments of shaders in comp and then transmitting them into the actual cg.

ThE_JacO
12 December 2008, 03:11 PM
More or less.
Again it depends from where you go.
Shading, when it comes to the higher level of it (RSL, hypergraph/rendertree, phenomena) tends to be fairly segmented and linear operations, and magic numbers often play a big part.

At several entry points in that linear progression you can output the framebuffer, so you end up with something like albedo, ambient, BRDF diffuse, occlusion, specularity, specular colours, masks etc.

Those become the first stage of output, and then comp, or more recently shader tweaking, TTT (turntable tools) and relighting become a faster way to iterate look-dev.
Once you find out magic numbers and sweet spots for how those things combine together and how you can go two ways:
You can keep all the granules alive, and keep outputting all these passes out for pre-comp or comp to deal with them, or you can take the magic numbers and reduce the latitude of the parameters that could need changing, and put them back into the shader to output things more "baked" and consistent at render time, and reduce the data throughput and storage impact (the latter less and less relevant these days, network pressure instead still plays a big part).
That's where it affects look-dev (and what constitutes look-dev is already a blurry area anyway).

Why and how you do that, again, depends from the pipeline and the size of the floor, and findind that point where amount of control and freedom don't compromise consistency and speed.

MDuffy
12 December 2008, 08:39 AM
I'm not familiar with those cool big pipelines, so this stage is a surprise for me. I thought lighters adjust the shaders and rely solely on artistic llcence, ha-ha. I also thought lighters tweak the textures to make the final renders. Ok, I understand the shaders are adjusted as close as possible to realworld values, but how they get tested without lighting? How can you know that this will look ok if not tested with the actual lighting?
I can only imagine some 360 degrees turnaround test renders, but still, in relation to what environment?

Well, when you have multiple lighters working on the same sequence, you ideally don't want them to have to tweak the shaders to get the look that they are after. Not only does this take more time (and sometimes break the pipeline if all the shader parameters aren't promoted up to a settable/animatable level), but it also makes it difficult to keep the look consistent among several artists.

Generally a reference light setup will be made for the show, or for each sequence in a film. The texture artists and look dev artists will make sure the objects look good under those lighting conditions. Then if needed, several variations of the object and/or its shader parameters will be published out for use by the lighting artist. Likewise, a lead lighting artist/TD will generally set up the overall lighting scheme for the set or sequence, and publish that out as well. Then it is up to the individual lighting artists to take the set lighting preset and the surfacing preset, and tweak the lights as needed on a per-shot basis.

Lighters shouldn't be tweaking textures, just like they shouldn't be tweaking geometry. If any texture or shader or geometry problems show up, they should be kicked back as retakes to the appropriate departments. Likewise, lighters shouldn't be tweaking shaders either. Lighters should only be concentrating on the lighting (and often compositing) of the scene.

Now, I'm not saying that in practice many lighters don't wind up tweaking everything under the sun in order to get their shots to work. They do. They just shouldn't have to. It is messy, often hard to reproduce across multiple shots, and generally a waste of their time.

Cheers,
Michael Duffy

mister3d
12 December 2008, 12:39 PM
Thank you MDuffy, this really makes sense regargding many people working on the same piece.

islepaal
12 December 2008, 06:29 AM
it reminds me of sounds mixer ?

monkeysweat
12 December 2008, 07:47 AM
wow, I feel even more unqualified for this type of work than before. How is it that this gets skipped in so many college classes? Is this the type of lingo, and workflow you only gain through work experience?

Wiro
12 December 2008, 12:43 AM
...lingo, and workflow you only gain through work experience?


Yes. And if you hang around tech-heads like Jaco you'll just expose yourself to all the more of it ;)

Wiro

ThE_JacO
12 December 2008, 01:03 AM
Yes. And if you hang around tech-heads like Jaco you'll just expose yourself to all the more of it ;)

Wiro

I pity the fool who goes for that :)

On a related note: Schools won't teach you much when it comes to pipelines and production lingo for a number of reasons. Marginally because of incompetence, but also because there's no real dictionary for pipeline and production work, and most of these things have several different shades of meanings, and sometimes will mean nearly opposite things in different shops.

You should try a dinner with a table of pipeline and rendering engineers to catch a glimpse of it, entree, main and dessert are normally spent arguing about terminology. Only occasionally, and only around around the time for scotch and cigars (and no sooner) people have all levelled on common grounds and are drunk enough to actually start discussing the topic that started the debate.

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