Is there a downtime model previewer?

I am making soccer shirts / shorts / socks from Soccerclubs arround the world (lol, I finnished actually the whole Dutch premier Division, which are really nice). It keeps me busy actually, but during the down times of second life, I cannot test them. Is there a way I can test them during the down time.

I am familair with GMax, but is this compattable with secondlife models?

Since I can't say much helpful about third party previewers, I'll let someone else answer that.

There's the preview grid, but I don't know if your account is old enough to be on this version of it. It's also not always up, if there isn't a new version to preview yet. However, when it is up and you can get on, it's great. You get a bunch of extra L$, and nothing you do over there affects the main grid. So you can upload all you like, see what things look like on your avatar and in different lighting conditions, and never spend a single real linden.

On the downloads section of this site, you'll find the avatar mannequin files. They come in Poser and OBJ formats. The poser models can be viewed in Poser and DAZ Studio. The OBJ's can be viewed in almost any 3D modeling program. You can test your clothing on both model types.

As for Gmax specifically, if it can import OBJ models and apply textures to them, you can use it. I can't remember off hand what it can do and what it can't. I've used it maybe twice ever, and that was like 2 or 3 years ago. A quick Google search did reveal this "single script for importing 3D Studio .ASC and Wavefront .OBJ files", so I'm assuming it can't do it natively, but it can if you install that script. Since Gmax was discontinued last year, it's pretty tuff to find actual documentation on it.

If you're looking for free software that is current, I'd recommend DAZ Studio, the free alternative to Poser. You can use it not only to test clothing, but also to make animations for SL.

You can download the uv-mapped avatar as Wavefront .obj file from the website. Any 3D program capable of importing that format could be useable as offline previewer. I've tried that in Blender and it works well. I'm not familiar with what people here commonly use.