[Kazan]

I need you to help me figure out how to generate SORTNORMs in the POF 3D model BSP data... i haven't a clue what they are

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FreeSpace 2: The Babylon Project Effects Nerd and Programmer.
http://freespace.volitionwatch.com/babylon

Did you say you wanted your head used as a soccer ball?

[JarC]

 

Originally posted by Kazan:
figure out how to generate SORTNORMs in the POF 3D model BSP data... i haven't a clue what they are

Hey Kazan   Excuse me for jumpin in here, I happen to know a bit bout these, albeit not exactly related to the POF format but from a math point of view. So I may be able to help out here if you have no objection...

I'll try a simple example to illustrate what sortnormals are...

Picture yourself a cube which is centered around 0,0,0, now picture each axis being a flat plane instead of just a vector...
These planes will subdivide the cube into 8 equally sized, smaller cubes, a process that can be repeated infinitely...

I have like you, however no clue how these are used in the IDTA data other than that if the various offsets turn up a non-zero value, the object should be subdivided and only for the poly's within the specified bounding box....

If I am not mistaken, the use of sortnormals allows you to approximate size and volume a lot darn faster than calculating the exact values...so basically they would be used in collision detection I guess

Oh, before I forget...they are usually  oriented perpendicular with their associated axes


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JarC (ICQ) "Dave? Will I dream?"
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[This message has been edited by JarC (edited 04-27-2001).]

[Eternal One]

 

Originally posted by JarC:
 Hey Kazan     Excuse me for jumpin in here, I happen to know a bit bout these, albeit not exactly related to the POF format but from a math point of view. So I may be able to help out here if you have no objection...

I'll try a simple example to illustrate what sortnormals are...

Picture yourself a cube which is centered around 0,0,0, now picture each axis being a flat plane instead of just a vector...
These planes will subdivide the cube into 8 equally sized, smaller cubes, a process that can be repeated infinitely...

I have like you, however no clue how these are used in the IDTA data other than that if the various offsets turn up a non-zero value, the object should be subdivided and only for the poly's within the specified bounding box....

If I am not mistaken, the use of sortnormals allows you to approximate size and volume a lot darn faster than calculating the exact values...so basically they would be used in collision detection I guess

Oh, before I forget...they are usually  oriented perpendicular with their associated axes

Quite good math-point-of-view description you got there, but it's not entirely that way. A lot more is involved, so much that I'd rather not write it all here  

But a cube is the worst example you can pick, it's a special case that hopefully Kazan takes into account when he builds his converter.

Sortnorms are the heart of octree generation and the only thing that's even a bit hard to code in a converter, I'm really looking forward how you'll pull it off Kazan  

[JarC]

   

Originally posted by Eternal One:
But a cube is the worst example you can pick, it's a special case that hopefully Kazan takes into account when he builds his converter.

I know, but since he indicated not to know what they are, I figured a cube would be the easiest to demonstrate the recursive pattern (and the inherent trap coz in a cube it would go on infinite).

Kazan, if you want more theory, you can find lots of stuf to study up on in one of the  BSP Tree Faq's

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JarC (ICQ) "Dave? Will I dream?"
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[This message has been edited by JarC (edited 04-28-2001).]