Modeling in Activeworlds : efficient modeling

1. Choose your modeling program

Modeling is make your own 3D objects by using a modeling program. Which modeling programs do you have ? On Wikipedia you will find a nice overview of the most comman modelling programs . (This list is very complete, but there are always new programs or still unknown ones.). A lot of modelling programs are too expensive for the use in Activeworlds , and these programs are rather for other purpose , e.g. to make animated 3d-movies). However, you will find in the list a lot of freeware modeling programs which are "open source".

2. File extensions

Not all models can be used in Activeworlds : in Activeworlds, you can use these files extensions : .rwx .cob en .x

.rwx -> this file extension is used in Renderware, this program doesn't exist anymore, but with Notepad (=freeware) you can still use the Renderware commands, and you will find the commands in the help-pages of the Activeworlds menu.
.cob -> this file extension is used in Truespace, the official site of Caligari isn't available anymore since july 2012 , so you will need to search to download the software elsewhere on the web (freeware)
.x -> this file extension is used in DirectX , this file extension can be used in several modeling programs (e.g. Wings3d )
There also exist conversion programs, which can convert there file extension of another program into an entension that can be used in Activeworlds. Accutrans, Polytrans and Kerkythea are 3 conversion programs, Accutrans can convert into the .rwx entension.

3 .What do you need to know about models before modeling ?

A. Models on the internet

Attention : on website the internet objects as easily offered as "low poly" models, but are not always suitable for 3d-real-time environments. That's why it's better to search for models which have been made for this purpose, you will have to search for "real-time environment 3d models" .

B. Een low-poly(gon) model

If you want to make a low-poly model : this is a model for which the effort has been done to get to a minimal number of polygons. Polygons are the number of triangles of which the model is made of. Almost every 3d program use divide their models into these triangular shapes, which means for instance that every square shape consists of 2 polygons (2 triangular shapes).

What do you need to do to make such a low-poly model ? If you don't see it, don't model it : don't model the inside of a cilinder if you cannot see it from outside. Details on a surface of a model can be replace by textures , and you can use masked pictures, instead of starting to use a lot of extra polygons for it.

C. How many polygons does a model need to have ?

A model with 10000 polygons : this is too much ,even for a large building
A model with 1000 polygons : is still too much, it's only suitable for large and complex objects
A model with 100, 200 , 300 , 400 polygons : is better and acceptable in the world
Below 100 polygons : here you have a very good model.
* Complexity : It is obvious that a kitchen table is less complex than a piano, so the table will have to be made with less polygons.
* Importance : How important is the model in your 3d scene ? Is it used in the background ?.Then use low poly models. It the object used very frequently ? Then keep it also as low poly as possible. If the object is an attraction in your world, then you use a higher number of polys for it. Examples : a high-poly christmas tree : it's ok because it's an important object in your scene . Teacups;plates : are less important -> low poly.
* Function : how many people will see your scene at the same moment ? If your world is a building world, then you will need to know that the builders will probably choose the high-polygon models for their builds ! If the world isn't a building world, then you can easily limit the high poly object or spread these objects into more "quiet" areas.

D. Optimalisation of the models

* Curves : When you are modeling, you need to check if the curved objects (cylinders, spheres) don't have too many vertices and surfaces. Models which are just a bit less smooth are better for a 3D real-time environment. The perfect round shape in a 3d-real-time environment is rather angular. For instance, if you want to model a plant, then it"s better to use a 6-sided cylinder instead of a 16-sided : 16 sides for a stalk is really excessive.
* Nurbs : avoid too many surfaces, avoid "nurbing" , example of nurbing :

* Subdivisions : avoid unnecessary subdivions for square surfaces. In certain modeling programs (3ds max, Wings3d,Accutrans...), you will notice that models are divided into too many polygons : the reason of this is often to improve the lighting upon the model , but is not needed for Activeworlds. A flat wall consists of 2 square surfaces for the 2 sides, which equals 4 triangular polygons. If you have a wall model that consists of 64 polygons, then it better to avoid this model and use the models with 4 polygons. In Accutrans, you have the option the reduce the number of polygons.

* Avatars : if you are using a lot of avatars models for your world with sequence commands , this could affect the framerate, then it's better to model them as "collision off", this will make the model "solid off" in your world. Collision off does not work for masks and transparency. For transparency, you can use the opacity command (version 5.2).
* Wireframe view : You can view the number of polygons of an object in almost every modeling program. In Activeworlds however, you can't see the number of polygons, but since version 5.2 you can have a wireframe view of the world : Options - setting - video - wireframe rendering.

* Details : be careful with the number of polygons, the more flat surfaces, the better. Avoid modelling too many details. avoid too many polygons on the wheels , instead of modelling the dashboard, you can use a simple picture.


More info : using models in AW

You will find more info about this in AWTimes :