RWX avatars

Getting a 3D model out of a modelling program and into Worlds as something you can wear. The format is .rwx, RenderWare's text-based object script — it opens in a text editor, and that is the part that saves you when something goes wrong.

Expect an afternoon the first time. Most of it is conversion steps, and most failures are texture problems rather than model problems.

What you need

Tool	For
A 3D modeller (Blender is fine)	getting the model to the right size and polygon count
AccuTrans 3D	converting OBJ to RWX. This is the step nothing else does well
An image editor	resizing and flattening textures
CMPCreator	converting BMP to Worlds' own CMP texture format
A text editor	editing the RWX by hand. You will do this

You do not strictly need CMP — 8-bit BMP works — but CMP is what the client is happiest with and what the original content uses.

1. Get a model

Make one, or start from something existing. Import it with its textures intact, because you will need to know which texture belongs to which part later.

2. Cut the polygon count down

This engine is from 1995 and it is not going to render an 80,000-triangle model. Check the face count in your modeller's statistics.

Faces	Verdict
up to ~5,000	comfortable
~10,000	pushing it
more	it will hurt, and it will hurt everyone else in the room too

In Blender, add a Decimate modifier and pull the Ratio down — between 0.20 and 0.50 is usually the right neighbourhood. Watch the face count as you drag, and watch the model: past a point the silhouette collapses and a face stops being a face. Back off before that.

3. Position it

This is the step people skip and then wonder why their avatar is on its side, underground, or the size of a building.

Worlds expects a particular orientation. Lay the model out horizontally, facing upward, centred on the origin, with its midline on the axis running through the middle. A dimensions template — a reference shape at avatar scale that you import, line up against, and then delete — turns this from an hour of guessing into ten minutes.

Scale against the template too. Something around normal human height reads correctly next to everyone else; a model twice that will get you told about it. Delete the template before exporting.

4. Export to OBJ

Export as .obj into the same folder as your texture files. Keeping everything in one folder from here on removes an entire class of problem.

5. Convert OBJ to RWX

Open the OBJ in AccuTrans 3D and use Save with Options:

Choose RWX as the output format.
Turn on the material and texture export options — without them the RWX comes out untextured and you will be writing the texture lines by hand.
Save with a short, lowercase name.

6. Prepare the textures

PNG does not work. Neither does anything else modern. The client reads 8-bit BMP and CMP. Use short, lowercase filenames with no spaces — pompom.bmp. Long or mixed-case names are a reliable way to end up with a blank shape.

Flatten to 8-bit BMP in your image editor. Then, for CMP:

Put CMPCreator.bat, compimg.exe, cmpview.exe and your .bmp in the same folder.
Run CMPCreator.bat. It asks a short series of questions: language, output format, one image or several, the filename, and whether you want transparency.
It writes three files. Keep the .cmp and delete the .210 and .pa2 — intermediates.

Worlds recompresses textures on its own, so expect some pixelation no matter how clean your source is. Do not spend an hour on a 2048px texture that will be shown at a fraction of that.

7. Edit the RWX by hand

Open the .rwx in a text editor. Two changes.

Point the texture line at your file

Find the Texture line and set it to your converted texture, with no path:

Texture pompom.cmp

Replace the diffuse line with a surface line

Find Diffuse 1.0 and replace it with:

Surface 0.580000 0.150000 0.150000 TextureModes Foreshorten Lit LightSampling Vertex

Part	What it does
`Surface` + three numbers	How the model reacts to ambient light. These values are a neutral starting point — raise the first if your avatar comes out too dark.
`TextureModes Foreshorten Lit`	Correct perspective on the texture, and the model responds to the light in the world instead of being flatly lit.
`LightSampling Vertex`	Lighting computed at the vertices. The cheap option, and on a model this size the right one.

If your model has several textures, the RWX will have several ClumpBegin blocks — one per part. Do both edits inside every block, each pointing at its own texture. Missing one is why an avatar comes out with a correctly textured head and a white body.

8. Put it in the client

The .rwx and its textures go in the same directory. The RWX names its textures without a path, so the client looks for them beside it.

File → Console Properties...
Find the Avatar (URL) field.
Put in the location of your .rwx and press OK.

A local path works while you are testing:

C:\Users\you\avatars\mymodel\avatar.rwx

A URL works too, and is how other people see it — the model has to be somewhere they can fetch it from, not on your disk.

A custom RWX avatar. A model, a texture, and about two lines edited by hand in a text file.

Use http://, not https://. The client runs on a Java 6 runtime whose TLS stopped being usable years ago. The modified client can do https through its own fetch path; the plain client cannot, and an https avatar URL simply fails with no useful message.

9. When it does not work

What you see	Usually
Nothing loads at all	A syntax error in the RWX. You edited it by hand; read the lines you changed. A missing keyword or an extra number is enough.
The shape is there but untextured	The texture filename in the RWX does not match the file, the file is not beside the RWX, or it is still a PNG.
Parts of it are inside out	Inverted normals. Recalculate them in your modeller and re-export.
One part textured, the rest white	You edited one `ClumpBegin` block and not the others.
It is enormous, sideways, or buried in the floor	Step 3. Go back and line it up against a template.
Everyone in the room, you included, turns into the same default figure	Not your model at all. The client filters avatars against a list it fetches from the server, and when that fetch fails it silently replaces every non-default avatar with the standard one. In the modified client Tools → Avatars reads that state and tells you in a sentence.

10. Sharing it

Put the .rwx and its textures on any web host that serves plain files over http, and give people the URL. Both servers in this project can host content for you — that is what the built-in HTTP server is for, and docs/15-hosting-content.md covers letting other people host their own.

Keep the source. The model, the OBJ and the textures, somewhere alongside the finished RWX. Six months from now you will want to change one thing, and re-deriving a model from an RWX is not a good afternoon.