Samuel Benge nous apporta ses lumieres en ce 2007/08/22 15:34:
> Bill Pragnell wrote:
>> Nice image, all the nicer for the colour bleeding!
> 
> Thanks!
> 
>> Surely the Miller indices define the crystal planes, 
> 
> Yes....
> 
>> so you can use them
>> directly to define your intersection planes (i.e., no knowledge of angles
>> required)?
> 
> No. I wish that were true, because it would make everything much easier. 
> Now, it *might* be true for cubic crystal systems, but I have to check 
> on that. For hexagonal systems that theory just doesn't hold.
> 
> Look at the attached image. If we were talking just straight normals 
> here, the numbers would be decimals or very large integers. Instead, we 
> have angles represented by three small integers, ranging between -1 and 
> 1 (they can be higher, I've seen them as high as 6).
> 
> I don't understand how the Miller indices work, but I know it has to do 
> with how molecules in the crystal are offset from one another. The 
> Wikipedia article just confused me, as I have no formal training in 
> higher mathematics.
> 
> If you have a way to calculate the normals for single faces (not the 
> angle between two faces), by all means, let me know! Otherwise, I'm off 
> to try the answer via Google....
> 
> Sam
> 
> ------------------------------------------------------------------------
> 
intersection{
plane{Miler_indice, 1}
.
.
.
material{...}
}

-- 
Alain
-------------------------------------------------
Rebellion against tyrants is obedience to God.
Benjamin Franklin

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