jos_t_tarigan

12-09-2008, 11:46 AM

Hi,

I notice from most program I got, they always keep the original position, sum up the transformation, and then transform the position eg: vertex A at 0, speed 3/second, 1st second calculation is 0 + 3*1, 2nd second calculation is 0 + 3*2.... i-th calculation is 0+ 3*i.

I try to change the structure so it keep the current position instead of the original eg: 1st second calculation is 0 + 3*1, 2nd second calculation is 3 + 3.... i-th calculation is 3*(i-1) + 3. And since 3*(i-1) is previous position(calculated), i think it will be better in performance since we dont have to do another multiplication.

But i cant find any sample program that use this solution. why is that? is there any problem with this one?

thanks in advance

sorry if this is a stupid question ;) im new with openGL

I notice from most program I got, they always keep the original position, sum up the transformation, and then transform the position eg: vertex A at 0, speed 3/second, 1st second calculation is 0 + 3*1, 2nd second calculation is 0 + 3*2.... i-th calculation is 0+ 3*i.

I try to change the structure so it keep the current position instead of the original eg: 1st second calculation is 0 + 3*1, 2nd second calculation is 3 + 3.... i-th calculation is 3*(i-1) + 3. And since 3*(i-1) is previous position(calculated), i think it will be better in performance since we dont have to do another multiplication.

But i cant find any sample program that use this solution. why is that? is there any problem with this one?

thanks in advance

sorry if this is a stupid question ;) im new with openGL