Texture maps - intended practices?

[Bart247]

Hi Everyone,

Apologies if this has been discussed elsewhere on the forum. If so please point me to that thread.

For Maya, I looking to document our internal pipeline and standardize some practices. How does V-Ray expect 8bit texture files to be applied to diffuse, roughness, normal maps etc?

For example:

Diffuse
ColorSpace = sRGB
FilterType = Quadradic or other
Filter = 1.0 - 0.2

Normal
ColorSpace = Raw
FilterTupe = Off?

I'm not sure which maps should be Raw and which maps should you turn the Filtering off on?

Please let me know what your pipeline conventions are or how V-Ray expects textures to be mapped.

[hermit.crab]

There isn't a general rule for Texture Filtering; the type of choice should favor quality. Filtering is required in Normal maps as well; it helps enhance the data once the texture has been scaled.
Usually, data textures should be exported as Raw as to not have data deviations. On import, the Color Space should match the texture's original color space.

[Muhammed_Hamed]

Hi Everyone,
How does V-Ray expect 8bit texture files to be applied to diffuse, roughness, normal maps etc?

Hello Bart247

-For diffuse, translucency (And any color maps) typically you want to set ColorSpace to sRGB, and use the default Maya filtering, which gets converted internally to Vray's Sharp Isotropic filtering(if you are using Vray 5) This new filtering type keeps high frequency details in your bitmaps with minimal blurring, it is also very fast to render
Vlado talks about this here, and it is mentioned in Maya's workflow here
If you are not on Vray 5 you will need to reduce filtering depending on the details you wanna keep, but don't turn off filtering completely for all the maps as it will affect rendering speed

-For Roughness, normal maps, bump maps (And other scaler or greyscale maps)..etc this is going to depend on where you got your 8 bit maps from. Typically you gonna need to set ColorSpace to RAW (this colorpace is actually just a Transfer Function, setting it to RAW means no changes happen to your bitmap)

-And you can go down on filtering to around 0.2 for bump/normal/displacement maps when needed to enhance on the details, like what Vlado explains in the link above

-Some places like Evermotion will have their 8-bit diffuse maps needing a linear transfer function, and some places bake sRGB to normal maps(as bad as this sounds), so not everyone abide by those rules.. you will need to inspect some maps occasionally if they don't give an expected result

-And finally if you are using the GPU engine Maya's filtering doesn't matter, the GPU engine has its own special filtering

Best,

Muhammed

[Bart247]

Thanks guys
your info is very helpful.

We have adopted a workflow at our studio of normalizing any roughness/reflection texture and dialing it in via multiplying it over white in the V-ray layered texture. I find we're reusing these imperfection textures more often now to create variations which is nice for an overall material library setup.

later.

[seandunderdale]

For animation you clearly want filtering on, but for high res still, 6000px+ Ive always switched texture filtering off to keep as much texture detail as possible. Would Vray 5 isotropic filtering be preferable, in terms of texture quality, than turning off texture filtering?

[Muhammed_Hamed]

Would Vray 5 isotropic filtering be preferable, in terms of texture quality, than turning off texture filtering?

Yup, give it a try. It makes a big difference, I used to turn off filtering for every map with Vray Next(for sharpness and detail enhancement).. This doesn't happen now in 5 with the new filtering
and could use filtering multiplier on bump/normal maps

I have done high resolution stills for Print in, up to 8 and 10k

[^Lele^]

For animation you clearly want filtering on, but for high res still, 6000px+ Ive always switched texture filtering off to keep as much texture detail as possible. Would Vray 5 isotropic filtering be preferable, in terms of texture quality, than turning off texture filtering?

On top of what Muhammed said, there are potentially huge performance considerations to turning filtering off.
If the texture is viewed with sub-pixel detail, and it isn't filtered, that will lead to it being treated like noise, and brute-force anti-aliased.
Depending on what the texure is driving, this could really make the rendertimes go through the roof, for no apparent reason.

Filtering should *never* be turned off (and not just for us, but for any engine out there): if the texture's too blurry, it's either too low resolution for its intended use, or a too-low mip is being rendered.
In the first case, the solution is obvious, in the second there should be ways in maya too to bias the chosen mip (In Max, that's the "Blur" parameter).

All this said, the new sharp isotropic filtering seems to get the job done nicely, as mentioned above.

[Muhammed_Hamed]

Thanks for your input Lele, I'm glad there is no visual difference now.. which comes first for many people
At the old days of Vray Next, plenty of people took the trade of slowdowns to have sharper texture details. This is not the case now

And for people using other Vray plugins, sharp isotropic is called Sharp Mipmap