Game Development Reference
In-Depth Information
That is all you need to create a simple scene graph. It may seem like an extremely
simplistic architecture, but it
d think. Each node you design
can add functionality and special effects to all its children nodes. Here are some
examples:
'
s more flexible than you
'
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Billboard node:
Sets the transform matrix of all the child nodes such that they
always face the camera. Use this for trees or light glare.
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Level of detail node:
A node that chooses one node in its child list for rendering
based on the node
s distance from the camera.
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BSP node:
A node that sets its visibility based on which side of the BSP plane
the camera is and where it is facing.
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Material node:
Sets the default material for all children nodes.
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World sector node:
Defines a 3D volume that completely contains all of its
children nodes. You use it to determine if any children need to be drawn based
on camera direction or interposed opaque world sectors.
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Mirror node:
Defines a portal through which the scene is re-rendered from a
different point of view and stenciled onto a texture.
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Lots more shader effects!
'
I
'
m sure you can come up with other cool stuff.
When the last three chapters were first outlined, I knew that I was going to leave
plenty of questions completely unanswered. The chapters covered too much in too
few pages. My publisher being willing, I could have spent more pages on 3D gra-
phics, shaders, and architecture, but even if I doubled or tripled my coverage of
these subjects I would still only scratch the surface. As with other chapters in this
book, my goal is to give you just enough knowledge to be dangerous and point you
to the next steps.
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3D Game Engine Design, David H. Heberly
n
3D Game Engine Architecture, David H. Heberly
