Using 3DS files with Anark

Asen

Summary
Anark Studio provides import capabilities to the well-used 3DS format. This format is often exported from various 3D packages. While this format is widely accepted and exchanged, each 3D package can write out various "flavors" of 3DS, each having their own idiosyncracies. This tutorial will guide you through some of the issues and advantages to using the 3DS file format. Some information in this tutorial may not apply specifically to the 3D modelling package you are using. Experiment with some of the ways your modelling package treats 3DS and the accompanying data to build a successful 3D workflow.

   
        
            Category
            Tutorials
        
        
            Author
            Eric
        
        
            Difficulty
            Beginner
        
        
            Time to Complete
            
        
   





Why is my model so darn small (or huge)?

   
    The internal Anark rendering engine does not pay respect to feet, meters or other systems. Rather, 3D coordinates are expressed as simply "units". 3DS files can have a tag for the unit system stored inside the file. If possible, adjust your 3D modeling package to use a "General Unit" scale or a "None" scale to that there is a 1:1 conversion of positional and rotational data from the modeling package to the 3DS file.
   
   
    In a default Anark presentation with the Camera's untouched and the Scale Mode of the project is set to "Fit to Size", the viewing frustum of the window camera will show objects between +500 and -500 on the X axis and +350 and -350 on the Y Axis. The illustration below illustrates how the camera, shown in blue, looks down the Z axis into an area shown by the cone.

   
   
   
    Therefore, considering the previous two statements, creating objects in your 3D modeling package between +500 and -500 on the Y axis etc. will yield a scale of the model that isn't immensely big or miniscule inside Anark.
   
   
    It is very important not to import 3DS files into Anark that require them to have scale factors over 100 units in X Y and Z in order for them to be visible in the Anark window. Doing so could yield objects that are not "click able" in the running presentation. If possible, scale the vertices and objects from within the 3D modeling package before export to try and minimize any post-import scaling needed to view the models.
   

Why is my model "lying" down and hard to work with?

   
    If a 3DS file is imported and placed into the timeline, it may appear "lying down" or rotated 90 degrees on the X Axis.

   

    It may seem easy to just rotate the object 90 degrees on the X axis and 'upright' the object, however doing so will immediately place the object into "Gimbal lock". Gimbal lock is a mathematical lock of rotational axis that prevents free movement when 2 rotational axis are aligned identically. The better way is to place the object into an empty group and rotate the object within the group to correct the rotation. Then the new group will become the root of the object that you will use for animation etc.
   
        
        Rotate your object into the correct orientation for working and viewing.

        
        
        
        Create an empty Group in the timeline be dragging a Group base object to the timeline.

        
        
        
        Drag your object that is correctly rotated into the new group

        
        
        
        Rename the Group and collapse the hierarchy. This will now become the root of the object.

        
        
   
   

3DS Legacy issues
The 3DS file format has been around since the days of DOS, and because of this, there are some legacy issues that need to be remembered

   
    Many 3D modeling packages can rename exported meshes to have no more than eight characters long. A mesh named "RoundThingy" could be renamed to "RoundThi" or "RoundTh1" depending on which modeling package you use. If naming is important to preserve in Anark, especially for scripting, name objects with only eight characters that are important.
   
   
    Models can be named the same in 3DS files which may or not be a problem in normal circumstances.

   

    However if you plan on addressing the object through JavaScript, having identical names could point to the wrong "object" when accessing them in the DOM.
   

Why aren't my textures showing up on my model?

   
    3DS files can reference external images for textures, however they must be in the same folder as the 3DS file. Internally, 3DS only knows of the image's name, not a directory path to the file. If your model is importing without any textures on it, try copying any texture files that are used in the model into the same directory as the 3DS file and import it.
   
   
    External texture files can only have 8 characters + extension in the name. 3DS files only remember images named in the old DOS (8.3) naming convention. Example: FABRIC23.JPG will be imported not RedWovenFabric.jpg.
   
   
    Even the best modeling packages or file converters can mutilate files or names on export. Often, it comes in the expense of texture files. If you use a texture whose name is RedWovenFabric.jpg, the modeling package may record its import pointer in the written 3DS file as simply "REDWOVEN.JPG" or "REDWOVE1.JPG"
   
        
        Unfortunately, many 3D packages will not give warnings which textures are expecting truncated or changed names in the 3DS file. If you are unable to determine how your 3D software is changing the internal name of the reference file, you may need to rename the texture file to 8.3 format before using it in your modeling software.
        
   
   
   
    GIF files are not imported into Anark Studio, If GIF files are used as textures, they won't be imported.  Use BMP or TGA.
   
   
    Avoid using JPEGs for textures as they become uncompressed images internally in Anark and will be re-compressed producing more compression artifacts. Use .BMP or .TGA formats wherever possible to preserve quality.
   
   
    Bump maps are not supported or rendered at this time.
   
   
    Depending on what kind of system your presentation will be played back on, the 3D graphics card may only allow 2 textures to appear on a model at the same time (eg. Diffuse + Reflection). So, if you have textures on Diffuse, Reflection and Specular simultaneously, the Specular channel may not render on some cards. Try to limit multi-texturing to just 2 channels.
   
   
    Diffuse textures modulate (blend) with the diffuse color, so if the diffuse color is black and there is a texture on the diffuse channel, the model will appear black. Make the diffuse color white if you intend to show a diffuse texture.
   

Power Tips with 3DS

   
    Instancing is supported in 3DS and is imported as instances in Anark Studio.  If you are building massive data sets with repeating objects, like an interior of an airplane, "instance" the seats instead of performing a "copy" in your 3D modeling software to save memory resources and file size.
   

tc

很经典，很实用，学习了!

tc

水。。。

C.R.CAN

有意思！学习了！

tc

我无语！

奇

心中有爱，爱咋咋地

晃晃

再看一看，再顶楼主