Second Life™ is technically complicated. Fortunately, most users generally don’t have to deal with the technical issues. We can just cruse around enjoying SL. However, if we make clothes, we are going to suffer from what we don’t know.

Foxes – Fleece Jacket – Grey by claudagger, on Flickr

DE Design has a new post up that appeared in Fab Free. See: Fitted Mesh. There is some good stuff and some tings I take exception to. 

The article does a good job of showing some of the problems with fitted mesh. When it comes to explaining why there are problems… well… there are lots of confusing statements I consider technically inaccurate. As I read the article I started to wonder if the author has fitted mesh and classic rigged mesh confused. I’ve read the article a couple of times trying to decide. I am still not sure. I think it is confusing because it is unclear whether it is the classic avatar body or the new mesh bodies that are being talked about. At the end of the article in the last paragraph it seems mesh bodies are what was in mind.

The information about what designers may intend and the viewpoint of consumers is new. The idea proposed is that new users probably think ‘Fitted Mesh’ clothes are supposed to fit. When thought about that is sort of a ‘Duh!’ moment. But, I’m so used to fitted mesh not fitting it never occurs to me someone might think it should fit. So, they have a good point.

The Lab peeps are versed in computer technology not psychology. So, they may never have really got into what the label ‘fitted’ mesh would denote to new users. I can see where the label adds more confusion to learning SL. I don’t envy the Lindens the job of coming up with labels that mean something and yet are not so technically accurate and complex it scares users off.

Then there is the idea of what designers may intend. Some fitted mesh is not going to fit any body without the use of alpha layers or drastic shape changes because the designer was correcting for problems in the design of a specific body.

While I appreciate the idea that designers use alpha layers to, in some cases, correct for skin poke-through as a design choice, I think it is way more accurate to say skin poke-through is just a technical limitation of the under lying system and alpha layers are the standard work-around. That is true in more places than Second Life.

In Blender when animating an avatar with clothes we can use cloth and set parameters that allow flexi like swishes without penetrating the skin or having skin poke-through. The cost is Blender renders such scenes in frame lengths measured in minutes per frame, not frames per second. In Second Life we do not have ‘cloth’ like Blender cloth. SL has to render in real time. Blender renders ‘off line’ or in ‘non-real-time’. Blender creates a movie frame by frame taking as long as needed for each frame. Later the movie is played at 29+ fps and it looks like real time movement.

Blender tutorial for cloth clothes: Create animation-ready clothing in Blender. The tutorial shows what is possible in Blender. Notice that the weight painting we use is replaced by ‘cloth stiffness painting.’ There is no wight painting for the clothes in the example. The render time has to be ridiculous. That type of cloth is not part of Second Life.

In SL the render system is cutting as many corners as it can. One of the results of that optimization is the need for alpha layers to hide parts of the avatar to avoid poke-through.

If a designer chooses to make close fitting clothes, no matter which mesh body or even the classic body, they will need to use alpha layers. It is a limitation of the real time rendering system we have in Second Life.

In Project Sansar we will likely see the same corner cut. I expect the problem to be less of an issue because of other design considerations. But, there will be a poke through issue. Whether we have alpha layers or use another technique to hide that problem/limitation, we can only guess.