Linear workflow button obsolete?

[mattsmith]

good tip, thanks!

[everythinghasfresnel]

While it may not be an entirely 'proper' workflow, the Linear Workflow option is one of the huge appeals that V-Ray has over mental ray. What a convoluted mess that is. I dread the day when I have to start using those blasted gamma correction nodes for every texture and color swatch again. And to be honest, the whole "Texture Input Gamma" attribute in the V-Ray attributes dropdown isn't any better. I haven't figured out how to script it or add the attributes to multiple nodes at once. Maybe there could be a checkbox that handles all applicable texture node and color swatch gamma values at once. It could be called "Linear Workflow", and reside under the Color Mapping settings.

This makes me wonder what the 3.0 workflow will be like. Kind of thought it would be officially announced by now. I guess Maya users will have to wait a few months longer.

[vlado]

This makes me wonder what the 3.0 workflow will be like. Kind of thought it would be officially announced by now. I guess Maya users will have to wait a few months longer.

To be honest we haven't decided how to approach that; I wanted to wait and see if newer Maya versions will bring something new to the table.

Best regards,
Vlado

[snivlem]

I think Autodesk are too afraid to break legacy workflows in Maya - regarding linear workflow. But that's a little off topic

I feel that the linear workflow button is terrific and I hope it stays too. Even if you hide it in the UI. While it may not be technically correct, it makes a massive difference to our workflows in terms of ease of use and time.

[hortenIX]

well, i read that.. and it s more confusing..

http://forums.chaosgroup.com/showthr...orrection-quot

"Linear Workflow checkbox and Enable Input Texture Correction are two identical options and if the same gamma value is used in both of them they should produce the same result.
The problem is that Linear Workflow checkbox doesn't influence all channels - for example it takes into account Diffuse channel but not Reflection one.
Color Slot of the VrayLightMtl is also not taken into consideration and that's why the result is different than what you are expecting.
Our recommendations are to use Input Texture Corrections instead of Linear Workflow checkbox in order to avoid such issues. "

so it means that using the check box linear workflow doesn't work, or is not 100%correct.. ??

the problem is, when you don t use the checkbox "linear workflow", if you have a shader with a solid color, adding a gamma correction node in the color is a big loss of time in production, same as clicking enable gamma correction for maps, & if you need to control all your maps, that s not really an improvement at all..

"linear workflow" check box is for me the best way too, fast and reliable, one click solution, but reading the above quote means that it doesn t take all params into account so the results are wrong.. ??

[vlado]

"linear workflow" check box is for me the best way too, fast and reliable, one click solution, but reading the above quote means that it doesn t take all params into account so the results are wrong.. ??

The checkbox works, but there are a few considerations:

1) It corrects the final result from the entire shading network for a texture slot (f.e. the diffuse color) rather than the individual colors/textures. This may or may not matter much, but the results are generally different.
2) It is not consistent - it works for some materials, but not others (we generally forget to implement it for new materials).
3) For some material slots it is really difficult to determine if colors should be automatically corrected or not - f.e. reflection color textures, or translucency color textures in the 2-sided material, or volumetric textures etc.

Best regards,
Vlado

[hortenIX]

well, if you recommand to use "Input Texture Corrections" ,
a good way to improve the workflow would be to add in the attributes "texture input gamma" even if no texture is used,
it would avoid having to create an extra gamma node if the color channel is just solid..

(or may be there's a workaround i don't know?)

[sharktacos]

I'm surprised to hear that the new materials don't work with the linear workflow button. Vlado could you post a list of which new materials those are exactly? Do SSS2 and the hairMtl3 not work with it?

The main issue for most of us here is that we don't want to need to make texture input gamma nodes for every single texture in a scene as this is very time consuming. Here's a workflow that I would propose (and am currently using):

Using the texture input gamma node means that you need to add this for every single texture in a scene one at a time which is quite time consuming. The linear workflow button, in theory, fixes 95% of things which then means you can use the texture input node for those remaining 5%. For example if you want to use a surface material as a flat color, Vray will assume you want it with no gamma correction (like it is a lightMtl) so you need to add the input gamma node to it. That means that you only need to make a few individual texture input gamma nodes for those exceptions, rather than for everything. This seems to me to be a workflow that a) is efficient and b) accurate. Best of both worlds!

This however assumes that the behavior of the linear workflow checkbox is consistent. So if we are going to keep the checkbox then the new materials should be made to work with it. I think it would be a shame to see the checkbox go.

[vlado]

I'm surprised to hear that the new materials don't work with the linear workflow button.

It's not that they don't work; it's just that we often forget to support it initially.

Vlado could you post a list of which new materials those are exactly? Do SSS2 and the hairMtl3 not work with it?

SSS2 supports it, hairMtl3 doesn't (but it probably will in the future).

Using the texture input gamma node means that you need to add this for every single texture in a scene one at a time which is quite time consuming. The linear workflow button, in theory, fixes 95% of things which then means you can use the texture input node for those remaining 5%. For example if you want to use a surface material as a flat color, Vray will assume you want it with no gamma correction (like it is a lightMtl) so you need to add the input gamma node to it. That means that you only need to make a few individual texture input gamma nodes for those exceptions, rather than for everything. This seems to me to be a workflow that a) is efficient and b) accurate. Best of both worlds!

I think, a much better idea, as far as textures are concerned, is to support the Maya color management options for textures. You have global options, which textures use by default, but you can override them on a per-texture basis.

Best regards,
Vlado

[sharktacos]

It's not that they don't work; it's just that we often forget to support it initially.

Got it. Hopefully you guys can implement that in the future ( assuming you keep the checkbox)

SSS2 supports it, hairMtl3 doesn't (but it probably will in the future).

Thanks. Are there other materials that do not support it currently?

The hairMtl3 is an odd duck, unlike most materials it hardly uses any diffuse and works mostly with 2 specs and transmision (which translate in to reflection and refraction in the passes). So given the unusual nature of the material, where would you recommend using texture input gamma nodes on it exactly? Were any used in the examples you guys made that (I assume) later became the presets?

I think, a much better idea, as far as textures are concerned, is to support the Maya color management options for textures. You have global options, which textures use by default, but you can override them on a per-texture basis.

The Vray check box is based on the incoming connection to the material. So if a texture is going into the diffuse it will apply a gamma correct, and if it is going into the bump it will not. It also works with color swatches in the material. The Maya color management system in contrast simply applies a gamma correction to every single texture regardless of its purpose. So when using this, if we assume that every material had color and bump, then we would need to make a exception for all of the bump maps (and normal maps, and displacement maps). That means that rather than needing to correct the rare 5% exception with the Vray checkbox, you instead need to correct every single material for its bump map. That is much more time consuming that using the checkbox is. That's why we all love the checkbox. The Maya color management system is simply not as well thought through. In addition to all of that, the Maya color management system does not work with swatches, so for these you need to manually insert gamma nodes with the color there (the Vray texture input gamma could not be used here). So that adds more hassle.

So because of all of that, I don't think the Maya color management is a better option. The checkbox is great.