PNG with tansparency on BRDF

[kostenurka]

Hi,

I'm rendering something like a cage. I created basic material, with deleted Difuse layer and added Vray BRDF. My texture is a PNG file with cutout (transparent zone). I can't make it to render and see trough the holes (my mapping is correct). To me it seems that BRDF material does not make any difference between JPG and PNG format.

Another thing I'd like to rich is a global transparency of my material (affecting the opaque part of my texture)..

Any suggestions how to?
Thank you

[renee81]

You have to put your png,in the opacity slot,when working with BRDF.

I am not sure I understand the second part of your post,could you explain a little bit more.

Renee

[fooprobe]

As Renee said, the opacity option will allow you to use a map, such as your PNG file, to establish opacity. White pixels in the map will be 100% opaque, black pixels will be 0% opaque, colors in between will be in between. If you use the map then the color box isn't used, so you can't simply change the color there to make the opaque part less opaque - you have to change the map so the white pixels are more gray.

[kostenurka]

Thank you,
To be honest that's how I'm working... but I can't believe that this should be the normal workflow. The png is a great invention, so many years I design my decals with transparency and simply load it in the bitmap slot, vray is smart enough to detect if jpg; png or anything else is used. I stopped to bother for creating extra b/w version of my decay, now brdf requires it back.
Doing what emil proposes means to pre_ set my transparency in photoshop by certain grey value!! This is really restrictive in terms of creativity( if i understood right)
Thanks antway

[fooprobe]

Oh! You're talking about the "use color texture as transparency" option in the diffuse layer of the standard material. I don't know if that option exists yet in VrayBRDF.

But keep in mind that having separate transparency maps is pretty normal workflow generally, and takes about 3 clicks in Photoshop. and png's also "pre-set" your transparency. i don't understand the difference, unless you're suggesting using a value in the material to reduce the maximum opacity. if so, then just use the multiplier next to the map in the opacity slot - less than 1 = more transparent

[fooprobe]

and i've never found that VfR automatically detects PNG files and uses their transparency. have i been missing something?

[fpedrogo]

and i've never found that VfR automatically detects PNG files and uses their transparency. have i been missing something?

Yes, it worked, but the .png need to have the transparency areas bake on it. It will not work with colors, it needs a transparency png and how you mentioned, we need to enable "use color texture as transparency". This only work with the diffuse layer. If you add a reflection layer, you will have to add the alpha to the reflection layer to avoid reflection on the transparency areas. Also, it is not available in the BRDF material yet.

[fooprobe]

Right, you have to turn on that checkbox, it didn't automatically detect the png transparency.

unrelated, but why is the VrayBRDF layer called that? Isn't BRDF specific to reflections? Why is the whole layer (including non-BRDF components) labeled that way, but the "Vray Material" isn't? Confusing.