Hiya,

I have previously posted this topic and had some success, but have problems elsewhere now, any help is greatly appreciated!)

I am rendering an internal view of a shop and require a logo to be painted on the wall.

I have modified the logo in photoshop and basically made the background transparent [by using select logo, copy, paste and deleting the layer with the original logo] and saved as a .png

In Max 8, I made a multi/sub object with the background being the paint of the wall and the sub object as the text, when I apply the map onto the wall with a UVW modifier everything looks perfect in the viewport, but when I rendered a final image after a radiosity calc the alpha/transparency of the logo does not work and I get the background of the logo showing through!!?

I’m thinking it must be some render setting…

Any help is appreciated.

Many Thanks

Q.

I’m not sure I understand how you’re making this material.  Multi-SubObject would mean you have 2 (or more) different materials applied to different faces.  Sounds like you’d want something like Blend or Composite, to show an image over a material.

Can you post us an image of your render so we can see how it looks?  And explain in a little more detail how you have this material set up.

3DS Max Design 2011 64-bit - Advantage Pack
Dell Precision T5500, Dual Six Core Xeon X5650 @ 2.67GHz, nVidia Quadro 5000, 24 GB RAM, Win 7 Enterprise 64-bit
Minneapolis, MN, USA

Hi, I agree with Chris.

A quick fix would be to put a plane a few millimeters offset to the wall and apply the logo with transparency, then uncheck cast shadows for that object (because is separated from the wall it will cast shadows and we don´t want that). It’s a “dirty” solution, but easier and faster to implement… and of course, it works!

Cheers.

Q6600 @ 3.55Mhz / ATI 4850 1G DX9/ 8G RAM / 4 500G HD in RAID5 mode

Damn I’m good!

Sorry, yes I did use a composite material by the following method from a seperate post;

I set my logo image up in photoshop and then did the following [from a previous post];

5) In your original scene, clone your wall material as a copy to avoid applying the sign to every surface.
6) Click on the material type and change it to a Composite and select the option to retain the original material.
7) Click on the material slot for Mat. 1: and select a standard material or whatever you want to use.
8) Add the png you created as the diffuse color, the alpha channel will cause only the text to composite over the base material.
9) Adjust your tiling and mapping to position the sign on the wall.

As I posted above, the composite material in the viewport looks fine, but when I render the radiosity I lose the alpha/transparency of the logo image I made in photoshop and also the material of the wall [flat paint] becomes grey. I don’t think Dynamis post will help it will probably just recreate the problem.

I am working on the image today, so any help will be appreciated!
Thankyou for your help/reply!!!

Hi QuantumK,

I tried to reproduce the workflow you describe to create a PNG in Photoshop.
(Usually I’m using a different method and the TGA option in such a case.)

The alpha channel created in Photoshop is not “Premultiplied”,
Therefore uncheck the option in the Material Editor. (See Attachment.)
Box “a” has Premultiplied Alpha checked, Box “b”, unchecked.

I hope that is the solution you are after. Cheers!

ivan

	Attachment

Hi everybody,
I have a similar problem I can’ t solve.
I tryed several tutorials without result.

I would like to use multi-sub object but can’ t manage to make it work.
I need to render a classical wooden crate with a “FRAGILE” logo over.
I applied as first material a proper wood.
As second material I applied a standard black material giving a black & white jpeg as a map for the diffuse color of this second material.

Even if in the sample the result is what I’ m searching, when I launch rendering it just tender the jpeg mask over the wooden one.

What’ s wrong?
Can you explain me the simplest way to make it work?
I know I could place another layer over it and map it, but multi-sub object could be very useful to me in the future so I would like to learn how to manage it.

Thank you.

Marco

P.S.: I’ m working with 3ds Max Design 2012 but this topic is just my same problem.