# [Bf-committers] Particle experiments - looking for feedback

**Alex Mole
**
bf-committers@blender.org

*Mon, 03 May 2004 23:41:48 +0100*

Hi Leon
It should take about the same amount of time to work out the inverse
transform and multiply two particle points as it does to transform four
vertices of a quad [roughly speaking]. However, once the particle has
been inversely transformed, it will work for every face in the object.
So for an object with 50 faces, we're talking 2 inverse transforms vs.
200 forward transforms. I'd say that'd be a speed improvement ;)
I don't know enough about the guts of Blender to say for sure, but AFAIK
transforms are stored in component {translation,rotation,scaling} form
as well as a matrix, so you should be able to trivially construct the
inverse transform.
Again, feel free to ask for advice on this if you want it :)
Keep up the good work!
Alex
Leon Turner wrote:
>* Alex - I wasn't sure whether transforming the particle co-ordinates /
*>* velocities to object space would help much, given that I need to cycle
*>* through many possible deflection objects. What do you think?
*