It's been a while since I last made something for TS3 (four EPs' time) but I'm pretty sure the fundamentals haven't changed.

What I did:
- Select item in CTU, go to meshes, load LOD1, 2, 3 (for shoes), insert blank bump map, change name of mesh, hit commit.
- Save package. Reopen.
- Insert my new textures (in this case a multiplier and mask.) Commit.
- Go to Other tab, untick 3 channel, tick 4 channel (my mask has an alpha for fourth recolourable part, in troubleshooting I have tried both DXT1-1bitalpha and DXT5interpolatedalpha versions.)
- Enable all patterns, change design for all four channels, using standard solid colour misc pattern.
- Save (not save as.)

Now, in CTU, the preview recolours fine. I can see my mask is functional. But in game, when I try to recolour the item, I get hit with a nice error.



I've been trying to figure out what the issue is and have built probably half a dozen packages from scratch already just troubleshooting. Everything works when set to three channels which is rather infuriating.

The only thing that strikes me is that in CTU you need to create at least one pattern when you import your meshes, before you first save your custom package. Not sure that's the problem here since when I've skipped that step I think I couldn't set up any patterns at all, but maybe worth mentioning.

Many 3 channel items won't accept being turned into 4 channel items - it takes trial and error to find one that will (if possible, it's better to clone a 4-channel item to begin with). We've solved this problem for objects now, but it still exists for CAS content.

I had to check it as it is been along time since i did this...
-Cloned the cheerleader dress wich has 3 recolors
-After cloning i first enabled 4 channel RGBA in the ''other'' tab
-Then i add a new design(add new blanc) in the ''texture'' tab.
-Add the meshes and a thumb to it and choose ''save as''
-Reopen the file and enable the 4th channel(pattern D) in the pattern tab.
-duplicate the settings(key/type and name ) from pattern C
-replace the DXT1 mask with a DXT5interpolatedalpha mask DDS(the 4th color is the alpha channel but keep in mind the other channels can not interfear with the edits done on that channel, in other words, the white on the alpha channel should be black on the other channels(RGB)

edit,
In my testfile i didn't import any meshes or thumbs but i can not imagine it makes any diffrence.
Oops, i think it also replaces the original
Anyway, the 3 to 4 color convertion works as it should

Wich shoes did you try?

To be safe, I'd suggest copying in the mesh comments from the mesh of a four channel item too. Goodness knows what goes into those things, but it's important .

The meshcomments are the same.
Those contain:

slider enabled or not(FV)
3 or 4 TGI links.
Shader settings.
Ambient ''.
reflective ''
transparant ''
shininess ''
emission ''

and prolly:
UVscaling
GEOM zoom(when lower detail becomes active)
and others....

After dancing around a fire, sacrificing some goats, and rebuilding my packages a million times, trying something different for each one (including bloombase's steps), and devouring a lot of errors, I've given up.

The mesh I am working with is ancient, from 2009 (it's the pointy flats I once had up here at MTS), so I wouldn't be surprised if it were hiding some sort of luggage with it. It's been fixed about four times since, twice by me, and twice by the goodness of internet strangers, so I wouldn't be surprised. Mesh comments look clean and typical when compared against a Pets EP mesh I had lying around, but it's also been run through rigfix and god knows what else.

I will have to be content with three recolourable channels. To be honest, I had only planned the fourth channel to be used for buttons. I feel really silly having spent all this time just for itty bitty buttons that no one will probably notice.

Thank you both for your help!

I don't know wich shoes the pointy flats are but i just did the afShoesAnkleCLowHeelPointy00_dOrsayFabric and made the knot the 4th channel.
All works fine(also in CAS), want me to write a tutorial?

My pointy flats are a modified mesh of the AnkleCLowFlatRound00_balletfabric. You needn't write a tutorial. I just made the button an unrecolourable overlay which I think looks nicer in the end.