Transparent texture projection using Arnold

[Anonymous]

I've been struggling for hours over this and could really use some assistance.   I'm using a PNG and projection to put a symbol on a mesh.  Everything works correctly except the transparent portions of the symbol.   For the life of me I can't figure out how to either create a transparency map to make this work.  I tried mapping the texture to an aiStandardSurface and setting it that way as well without any luck.   

I've read a few other posts on the forum about a similar issue and I can't get them to work either.

Thanks!

[mspeer]

Hi!

Just search in the forum for "Arnold transparency".

2 threads that might be helpful:
https://forums.autodesk.com/t5/maya-shading-lighting-and/transparency-renders-black-in-arnold/td-p/6...
https://forums.autodesk.com/t5/maya-forum/arnold-maya-2017-transparency-with-file-texture-showing-bl...

[Anonymous]

Thanks for the reply!  I have already read those and I don't want to say it doesn't work, it's more like I'm not comprehending some small detail.

As specified here, they say to add a color correct and a reverse node to a standard surface while using an alpha map for transparency.   When I do this, nothing appears at all.  Here's my workflow:

I have a symbol being projected on the left and right side of a ship.  If I connect the texture directly to the projection (DefenseLeftRight) it displays the symbol,  but with the square white edges which are supposed to be transparent.  When I send the right side to a standard surface it disappears entirely.  I tried adding the color correct and reverse, but still I can't get it to appear.  What am I missing?

[mspeer]

Hi!

Please upload a scene-file and include the 2 textures (tga, png).

[Anonymous]

No problem!  Here's a top down view of the hull.  The symbol on the left with projection works, but the material on the right doesn't.

I appreciate the help!!!

[mspeer]

Hi!

Remove the material node "aiStandardSurface29" out of the network and it will be displayed.

But the transparency and alpha functions of the projection node seem to be broken.

It does not work with Arnold and Maya Software Renderer.

You might try this on your own with a simple setup.

If you can confirm this:

Please report this problem (bug?) to Autodesk.
Help -> Speak Back -> Report a Problem

[Anonymous]

Mspeer - I had it configured that way originally.  I only inserted the standard surface as it was listed as a fix in a different post where the poster had the same problem I do.   It will project, yes, but without transparency.   

So you think that the issue is a bug and it is supposed to work?  Do you know of any other workarounds to make this work?

[Anonymous]

I think i found a workaround. You need to match the colour of your background. in my case  I want a metal material and an colourized logo on top of it. After you get to match the colours closely you can go and use curvature and ambient occlussion mask to bring in detail. What I need to figure out now is how to get the logo to appear "less" metallic - but i think with the first layeredtexture node i have all colour information at hand to do that.