question

Edwin Fuhrmann avatar image
Edwin Fuhrmann asked ·

Applying label on object with alpha map

bildschirmfoto-2021-02-23-um-000455.pngbildschirmfoto-2021-02-23-um-000445.pngbildschirmfoto-2021-02-23-um-000501.pngHello.

I have a problem and i can´t solve it which becomes really frustrating at the moment...

I want to apply a picture on an object using a alpha map. there is already a main texture on the object and i want to place the tetxture over it. i do a polygon selection for the area and aplly the texture on it and use another textue in the alpha channel of the object.

the alpha does not work and the poly selection is always white somehow (even without a texture on it)bildschirmfoto-2021-02-23-um-000511.png. changed the sequence of the poly selections but it won´t help. used the alpha map in the cut out oppacity channel in the object and unchecked the opaye option but i keeps looking odd...is there a prooper workflow way to do this because i am running out of ideas....thank you!

alpha for geometrylayer
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Edwin Fuhrmann avatar image
Edwin Fuhrmann answered ·

bildschirmfoto-2021-02-24-um-224120.pngbildschirmfoto-2021-02-24-um-224132.pngbildschirmfoto-2021-02-24-um-224153.pngbildschirmfoto-2021-02-24-um-224206.png

ok i finally managed to place the label using the node setup in the first screenshot. had to use the exact same uv transform node for the label and the alpha...the last problem is now that i am not able to get rid of the label on the top....i set the uv wrap to clamp but it is still tiling..if i uncheck tiling in the material setings nothing changes either..only one step missing here...any final ideas?


3 comments
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Instead of using Arnolds UV transform, use the OSL transform.

DOWNLOAD

You simplify the noodle since this transform sits upsteam, on the other side of your bitmap, and thus you only need to use 1 to control rgb and alpha.
I think I mentioned this earlier else I forgot, but its better to do it like that.

If you also use an OSL Bitmap look up instead of whatever you use to load texture now, you can easily avoid tiling by setting the dropdown to non tiling and it will work.

So if you kinda do - excatly - like my initial images, its the simplest.

0 Likes 0 ·

qwe.png


qweqwe.png


Try look here.
I made a custom bitmap loader that does all you need.


Download the shader called NonTilingTexture and wire it up like second image. Dont forget to download the Uv transform node as well.


shader NonTilingTexture
(
    string Texture = ""[[string widget = "filename" ]],
    point Position = P,
    float gamma = 2.2,
    output color Color = 0,
    output float Alpha = 0,
)
{
    Color = texture(Texture,Position[0],1-Position[1], "wrap", "default", "alpha", Alpha);
    Color = pow(Color,gamma);
}


0 Likes 0 ·
qwe.png (214.5 KiB)
qweqwe.png (62.0 KiB)

So something like this.
qweqwe.gif

0 Likes 0 ·
qweqwe.gif (1.1 MiB)
Edwin Fuhrmann avatar image
Edwin Fuhrmann answered ·

bildschirmfoto-2021-02-23-um-184501.pngbildschirmfoto-2021-02-23-um-184511.pngbildschirmfoto-2021-02-23-um-184516.png

i tried every combination but it doesn´t work at all.there is still some white around the label and i really don´t know what to do anymore....


2 comments
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Can you share the scene or send it to support@arnoldrenderer.com?

0 Likes 0 ·
Edwin Fuhrmann avatar image Edwin Fuhrmann Peter Horvath ·

i write you a mail..thanks for your help!

0 Likes 0 ·
Peter Horvath avatar image
Peter Horvath answered ·

This should be as simple as using the Alpha channel of the Arnold Material or a layer_shader. Here's a simple example of both: label.zip

I wonder what's different in your scene which makes it fail.


label.zip (350.6 KiB)
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Edwin Fuhrmann avatar image
Edwin Fuhrmann answered ·

Tried eversthing but i don´t can pull it of. the problem is i can´t use a layer note because material 1 is a complete shader and i want to layer the label on top of it. so i put the label in the base color of a new shader and try to combine them with a mix node or a layer shader but they don´t work..there must be a way for such a simple thing or am i missing something?

10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Mads Drøschler avatar image
Mads Drøschler answered ·

Hi, I know this isnt done in your host, but you can follow the logic of doing it in a nicer way than selecting polygons and treat it as a photoshop document instead.

Use the Arnold Layer RGBA node, and start from the bottom like in photoshop. so slot 8 gets the background texture.

Slot 7 gets the overlay and the alpha channel is stuck into slot 7s Mix slot.

That is it, you can then use a transform node to move your texture around separatly, scale it, make it look ace at the exact position, excluding the need to select polygons and greatly simplify your workflow making it flexible.

Do note I use OSL texture loaders, but your host can also load those, just follow the logic of stacking things up from the bottom like in photoshop and you will be fine.

ccc.gif


ccc.gif (578.1 KiB)
1 comment
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

thank you so far...i will try this later and tell you if it worked.

0 Likes 0 ·

Write an Answer

Hint: Notify or tag a user in this post by typing @username.

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Welcome to the Arnold Answers community.

This is the place for Arnold renderer users everywhere to ask and answer rendering questions, and share knowledge about using Arnold, Arnold plugins, workflows and developing tools with Arnold.

If you are a new user to Arnold Answers, please first check out our FAQ and User Guide for more information.

When posting questions, please be sure to select the appropriate Space for your Arnold plugin and include the plugin version you are using.

Please include images, scene and log files whenever possible as this helps the community answer your questions.

Instructions for generating full verbosity log files are available for MtoA, MaxtoA, C4DtoA, HtoA, KtoA, and Kick.

If you are looking for Arnold Documentation and Support please visit the Arnold Support site.

To try Arnold please visit the Arnold Trial page.

Bottom No panel present for this section.