Fluffy Sharkfin

Honesty! Anything else is just icing on the cake.

The situation is indeed alarming, fortunately the OP is not alone in their concerns and others have already begun ringing the alarm bells as you can see from this thread... Petition against new SL economy policy (of course that was from January 2005, but just because SLs final gasp has been going on for the last 15 years doesn't make the situation any less dire!) Seriously though, for anyone actually worried about the future of Second Life, I'd recommend heeding the words of one of the posters in that archived thread when he said thanks @Cristiano Midnight for the sage (and timeless) advice!

Local textures are available in Firestorm, you simply need to open the texture picker in the build window and select the Local radio button (see image below). Once there you can add textures located on your hard drive and apply them to objects in world and every time the texture is changed locally (i.e. each time you save the texture in your bitmap editor and overwrite the original) the texture on the in world object updates almost instantaneously. It's basically a 3D term that's been shortened for expedience, but retopology literally means the rearranging of the topology or "layout" of the polygons that comprise a 3D model, (which is pretty much the dictionary definition of "topology") 3D Coat is available for Windows, Mac OS and Linux. The reason you haven't heard of it is because while the creators of the app are great at making software, they really don't seem to have much of a clue when it comes to marketing, which is a shame since, in my opinion, it's one of the best pieces of 3D software available and is sold at a fraction of the price of other comparable 3D applications. 3D Coat does have some vector based tools and several other resolution independent options that are quite useful when working with high/low rez textures. It's well worth checking their youtube channels which contain a wealth of tutorial videos, they even have a feature in the app where hovering your mouse over certain tools and options and pressing F1 will automatically open a browser window to the appropriate youtube video tutorial for it.

A commendable goal, and one which other would-be creators should take note of and learn from, SL content would be all the better for it if they did!

Yes, that seems the most likely explanation. There are two fairly simple solutions to your problem, the simplest of which is one you've already discovered i.e. just avoid applying the texture to that area and have the edges of the texture end just before the deformation of the UV begins. The alternative would be to take that same UV grid texture and add it as an underlying layer in your bitmap editor. Then, using the grid texture as a guide, you can distort your texture so that it matches the distortion of the UV map you're seeing in the last screenshot you posted (in this case it looks like stretching the lace pattern at the edge of the texture by around 250-300% would compensate for the UV map distortion). As long as you're using the Local Textures feature this can be relatively quick and painless and will avoid having to re-upload the texture multiple times while fixing the issue. Since you stated in your OP that this is a full perm mesh that you purchased rather than one you created yourself I'm assuming you don't have access to the mesh outside of SL, so retopologizing isn't going to be an option in this instance, but if you plan on using Marvelous Designer in the future it's most definitely a process that you should try to familiarize yourself with. Having a clean topology that follows the form of the object you're modelling not only makes UV mapping simpler but can also make rigging mesh objects far easier and more effective than trying to rig the mesh output you get from MD. Personally I'd recommend taking a look at an app called 3D Coat, it's relatively inexpensive and there's a 30 day demo available so you can get a good idea of how it works before having to invest any money in it. It has a lot of tools specifically designed for the purpose of retopology and UV mapping, as well as a really nice paint room that allows you to paint directly onto a 3D model on multiple channels simultaneously (i.e. diffuse/colour, normal/bump & specular/shiny, all the maps you need for materials in SL). It's basically like a 3D Photoshop with Zbrush and retopology/UV mapping tools thrown in for good measure.

Applying a UV grid texture (like the one below) can help you discern if the UV mapping is uniform across the entire mesh or if some areas have been squashed or distorted in some way. That will give you some idea of the extent to which you'll need to distort your textures to fit the UV mapping of the mesh correctly when creating custom textures for it. As for deformations that occur due to the shape you're using try rezzing the mesh rather than wearing it, assuming the creator has uploaded it at the correct scale it should conform to the default shape used to create the mesh. As for reasons why this particular mesh is doing this, it's probably either because the creator didn't make the UV mapping uniform to begin with, or because they altered the mesh after applying UV mapping and in doing so compressed the UV, thereby causing the texture to become "squashed" on those polygons.

Since texture animation works on all texture channels you can make some very nice running water effects using a seamless fractal noise generator to create normal/specular maps & alpha channels, etc and tweaking the UV mapping on your mesh to control the speed/direction of the flow of the water.

All very valid points and I'd agree that the onus is on LL to fix the issues with the lack of incentivization for creating more efficient content (and conversely the lack of penalization for those creating poorly optimized content). That being said the fact that SL content creators are, as you put it, so "good at peddling snake oil" and are often looked upon by their customers (and SL residents in general) as experts in content creation, I believe they do share some responsibility when it comes to the information (and sometimes disinformation) that they disseminate. A large part of the process of improving the optimization of content uploaded to SL is going to involve providing residents with much better information on the best (and worst) practices involved in content creation, and the difficulty in doing that will depend a lot on how many differing opinions users are exposed to. If LL are saying one thing and various content creators are saying something completely different, it's just going to lead to confusion and the propagation of more bad practices.

The fact that the additional tails only became visible after being taken into inventory then re-rezzed is curious, and lends credence to the theory that it's using texture animation somehow (since texture animation is an object property that persists after the script that initiated it is removed, but can be broken when taking the then unscripted object back to inventory and re-rezzing it). Sorry to ask a really obvious question but you do have "Select Faces" selected in the build window and you've selected the tail face and not the face that corresponds to the body rather than the tail right? It's just the texture in the preview window doesn't look compatible with any type of texture animation and it's hard to imagine what method they could possibly be using to do alpha switching on the tail given what you're describing and the screenshot you posted.

I'm not sure I follow your math here Qie, or maybe we're thinking of slightly different methods. To illustrate here's an example tail alongside the uv layout and corresponding texture. As you can see each of the four tails use approximately 1/4 of the texture space (the other 3/4 being transparent). Adding a texture animation with the PING_PONG flag set would cause the tail to appear to move from side to side as that opaque section of the texture lines up with the uv mapping for each segment. Of course the limitation of this method is that you have to use the same texture and uv island layout for all versions of the tail and only modify the vertex positions of the mesh rather than having individual textures and uv layout for each version of the tail.

Some additional information on how exactly you "broke it" may help to shed light on the method being used to animate it.

It's hard to say for certain without inspecting the object in question but the most likely explanation for what you describe is: The body is one material and has a regular texture on it. The tail(s) are all sharing the same material/texture, but have different uv mapping, with the UVs of each tail being located in a different quadrant/section of the texture map. The tail texture appears in only one section of the image, the rest of the texture is transparent, and the tail "animation" is achieved by changing the offsets of the texture on the tail(s) to change which one of them is currently visible (most likely with the use of llSetTextureAnim). It's a crude but reasonably effective way of simulating animation, but before you use this particular method I'd suggest taking a look at animesh. It allows you to create far more realistic and efficient animated content than the various forms of "alpha swapping" that are currently in use.

The basic principle for creating LOD models is pretty much interchangeable between most traditional 3d apps so assuming you're familiar with the toolset in 3dsmax then your best bet is just to find one of the numerous tutorials in this sub-forum on how to make LOD models for SL mesh and follow along, ignoring any specific information regarding the blender toolset (or whatever app the tutorial is based on) and substituting the appropriate 3dsmax tools. Here's a tutorial created by Penny Patton that covers the basics and should help you get started Optimization Tutorial: Creating Your Own LOD Models! I'd also recommend searching the forums for posts related to 3dsmax just to see if there are any specific limitations that you need to be aware of or recommended workflows you should follow when preparing your meshes for upload.

The person that posted that image has already said that he did so because that is his personal preference style-wise. He then provided further examples of less stylized and more realistic character models (all of which you seem to want to conveniently ignore so you can harp on about the first image and how much you dislike the aesthetic). As far as animation goes, if you don't like that particular animated gif I suggest you follow the link I posted and read some of the articles, even better do a google search and learn a little about what IS possible rather than just declaring something is impossible simply because you haven't seen anyone do it properly in SL yet. The ceiling for quality of content is NOT defined by "the best stuff you've seen in SL", and if you try to argue from the position that it is you aren't going to win the hearts or minds of anyone that's taken the time to research what CAN be done.

Sorry, I'm not going to explain the meaning of the word "example" to you, go google it!