Drawing lines in Balloon3D?

Bert Freudenberg bert at impara.de
Mon Aug 28 08:47:47 UTC 2006


Rich Warren schrieb:
> 
> On Aug 27, 2006, at 9:50 PM, Bert Freudenberg wrote:
> 
>> Am 28.08.2006 um 03:26 schrieb Rich Warren:
>>
>>> Does anyone know how to draw lines in Balloon3D? I want to add 
>>> simple, straight lines to a surface graph (based on the surface graph 
>>> tutorial).
>>
>> It's not supported by the plugin. There are hooks for polylines in the 
>> API though, I once implemented those using Balloon2D (meaning they 
>> could not be hidden behind a 3D mesh). Very long time ago, not sure if 
>> I can find it - it was more a hack than anything else.
>>
>> Your best bet would be to just construct a tube mesh connecting the 
>> nodes.
>>
>> - Bert -
>>
>>
> 
> Well, that's disappointing. I was hoping to make lines that would appear 
> at a given width regardless of the distance to the camera. These would 
> be the X, Y and Z origins for a data surface, so  they would need to be 
> able to correctly penetrate solid objects.
> 
> The tube idea is probably the best bet--though they may disappear when I 
> zoom out.

You could adjust their width on the fly depending on current zoom factor 
/ distance, which would mimic a line primitive. You could also make them 
longer, something that a built-in line would not do automatically.

Doing this on your own is also more predictable - like, Direct3D would 
not even support wide lines, whereas OpenGL does.

- Bert -



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