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Subject: 

05b. UNIVERSAL MEDIA VRML DEMOS

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TIME: (see previous section)

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If you could see the 3D dragon previously, try these:



http://www.web3dmedia.com/UniversalMedia/demos/



When you load these "worlds" you should see fully textured (texture

mapped) objects in the scene. In other words, the detail of the world

should look similar to the 2D graphic button that you click on to load

the world.



Is this the case? Do you see "textured" objects, or are are the surfaces

of objects "flat" (solid color only; no textures)?



Texture-mapped 3D objects, such as these, take a considerable amount of

processing power since your computer must calculate not only the 3D 

geometry (form of the object) but it must also map (wrap) a bitmap image

(such as a JPEG, PNG, or GIF) onto the shape.



Although 3D accelerated systems (those that have a 3D processing board 

in them, which takes the burden of processing this information off of 

the main CPU) are usually fast enough to handle complex texture-mapped

scenes, those without special 3D hardware are often sluggish when 

rendering such scenes. 



To speed things up try changing the "rendering mode" used by Contact:



1) Right-click somewhere on the 3D scene.



2) Choose "Graphics" from the pop-up menu that appears. This can

   be tricky if the scene is animated (try moving your mouse a very

   small amount to trigger the menu!).



3) Choose one of these modes:



     - Textures (show textures when "checked")

     - Smooth Textures (best quality textures when "checked")

     - Dithered (dither colors when "checked")

      

Experiment with the above modes to see if you can turn texture mapping 

on and off. When done, try these modes:



     - Wireframe (points on the shape connected by lines)

     - Vertices  (points on the shape only)

     - Flat (flat colors)

     - Smooth (smooth colors)





You'll notice that the fastest modes have no textures and no colors, 

although the quality of the scene is quite poor as a result.



You'll also notice that making the window of your browser smaller

increases the speed (framerate) of the animation, because a smaller

screen area means the computer has to work less to change frames of

the animation.



NOTE: THESE ARE REAL TIME 3D GRAPHICS; AS YOU MOVE AROUND THE SCENE

      IT IS RENDERED DYNAMICALLY FROM THE NEW VIEWPOINT.

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Aaron E. Walsh  http://www.gridinstitute.com/people/aew/  617.350.7119

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