Someone please explain this alpha stuff ?

[angelyne]

Found this text associated with an item.  It's not the first time I see the "alpha" term and it's driving me crazy.  What does it mean and how do you work with it??

Take two of the alphable acessories series. Thanks to Dr Pixel for the inspiration. The necklace is stomach length and it is completely alphable. This set includes 3 necklaces and the mesh file.

[seventhson]

As I understand it, the alpha tells the game which parts of the bitmap file associated with a piece of clothing/accessory/whatever else are going to show up, and which parts are not. It's basically a big black-and-white image file; anything in white shows, anything in black doesn't. If you change the alpha, some bits of the clothing, say, will not be seen on your Sim. Or other bits will show up, depending on what you're doing.

Not sure what 'alphable' means, though.

[Renatus]

Heh, messy shorthand...

An alpha channel determines what on the mesh is transparent and what is not. Depending on the shape of the mesh, editing the alpha channel can be used to make the clothing/item seem to have all sorts of different shapes, so you can have recolours that all look quite different while they all use the same basic mesh.

It sounds like this accessory has an alpha channel that can be edited to make it seem to have lots of different shapes and lengths, very versatile. I don't know why they'd call it 'alphable' for that, it makes it sound more like it can have an alpha but doesn't, rather than it has an alpha channel that can be edited to give it different effects. Since I think alpha channels have to be built in, I think they meant the latter with their sloppy wording.

[idtaminger]

The alpha is essentially the blueprint for the clothing shape, if you will. By editing the alpha, you're editing the shape of the outfit, and, consequently, the look of the outfit itself.

It's like drawing a shape onto a piece of cloth and cutting it out. Depending on how you draw  it, the outfit you get is going to be different.

[J. M. Pescado]

Found this text associated with an item.  It's not the first time I see the "alpha" term and it's driving me crazy.  What does it mean and how do you work with it??

Take two of the alphable acessories series. Thanks to Dr Pixel for the inspiration. The necklace is stomach length and it is completely alphable. This set includes 3 necklaces and the mesh file.

In this context, "alpha" refers to an alpha map of an object. Which functions as described above. Meaning you can basically make parts of the object visible or invisible to create any similar type of object you want.

And if you don't know what it is, you probably don't care about it. It's someone else's problem.

[angelyne]

Thanks for all the answers.  The concept is still a little fuzzy, but that's okay.  I'm very hands-on and I never understand something unless I can do it myself.

The reason I was intrigued was that on another mesh, I had seen the mention "alpha removable".  It was an hair mesh, and the alpha removable part was refering to a part of the mesh.  That made it almost sound like it would be something easy to do.  But I don't think I'm awesome enough to do it yet.  Maybe one day.

[akatonbo]

The reason I was intrigued was that on another mesh, I had seen the mention "alpha removable".  It was an hair mesh, and the alpha removable part was refering to a part of the mesh.  That made it almost sound like it would be something easy to do.  But I don't think I'm awesome enough to do it yet.  Maybe one day.

What they mean by that they've created the mesh and UV map so that it's easier to see how to edit the alpha file to do something like, say, change the style of or remove the bangs/fringe, just by editting the alpha file in your graphics program, instead of having to screw around with altering the mesh itself. That way people who're decent at graphics stuff but know nothing about meshing can make quite different-looking recolors of that hair.

[Sleepycat]

The concept is still a little fuzzy, but that's okay.  I'm very hands-on and I never understand something unless I can do it myself.

If you play around with making clothes in Bodyshop(and a graphics program) you can edit the alpha for a clothing item and get a feel for what alphas do/are for