About File node Extra Attributes

[Reaversword]

We must use Vray Extra Attribute of file node "Bitmap Input Gamma" in place of the own Maya node "Gamma Correction"?.

For a linear workflow of 2.2, we must use 2.2 like valor for Bitmap Input Gamma, or 0.454545?.

One time do the gamma corrections correctly, the Color Mapping configuration for work in linear workflow must keep being "Linear Multiply", "Dark & Bright Multiplier" to 1 and "Gamma" to 0.4545?.

What we must understand for "negative colors"?. The same that the option "Invert" in the Effects section of the File node?.

[Morbid Angel]

you dont have to use the custom attributes for texture. You can use maya native gamma node. Or you can check (linear work flow) under color mapping. This will intern apply gamma correction to all bitmaps in the scene. Negative colors is an option if you want to use true 32 bit float ranges for passes like point world and point object passes.

[vlado]

We must use Vray Extra Attribute of file node "Bitmap Input Gamma" in place of the own Maya node "Gamma Correction"?

Like Dmitry says, you don't have to use the extra attributes, they are there for convenience. The value that you need for linear workflow is 2.2

One time do the gamma corrections correctly, the Color Mapping configuration for work in linear workflow must keep being "Linear Multiply", "Dark & Bright Multiplier" to 1 and "Gamma" to 0.4545?

The color mapping gamma should be 2.2 as well.

What we must understand for "negative colors"?. The same that the option "Invert" in the Effects section of the File node?.

No, it is not the same. Some texture maps, in particular displacement maps, or some other special textures, have negative colors stored in them. Normally V-Ray clips those colors, as they often tend to cause issues, but in the case of displacement maps you really need the negative portion. This attribute allows you to prevent the clamping.

Best regards,
Vlado

[pechart]

Or you can check (linear work flow) under color mapping. This will intern apply gamma correction to all bitmaps in the scene.

I thought the button only linearizes the color inputs of vray materials, not all the bitmaps? If you plug a bitmap into a blinn i.e. it won't be linearized, even if the "linear workflow" button is checked, as far as i know.

[vlado]

I thought the button only linearizes the color inputs of vray materials, not all the bitmaps? If you plug a bitmap into a blinn i.e. it won't be linearized, even if the "linear workflow" button is checked, as far as i know.

Actually it will be applied to Blinn materials.

Best regards,
Vlado

[pechart]

Hmm, okay. Good to know. Thanks!

[Reaversword]

thanks to all for the info!.

[snivlem]

Actually it will be applied to Blinn materials.

Best regards,
Vlado

Hi Vlado, is it possible to post a list of what is and isn't supported in the docs somewhere? Just so we know.

Cheers.