shreyas_potnis

15th March 2003 11:08 UTC

synchin dm's and ssc's
how dou you sync dm's and ssc's? like in many of UnconeD's presets (circuit city). i tried hard but couldnt get it. the ssc seems to move rotate in some other direction. then i tore down unconed's preset and found that is rotation around x axis is 1 in the dm, then it is -1 in the ssc. this worked for one axis, but when more than one axis had rotatio non-zero, then it doesnt seem to work.
can someone explain?

mikm

15th March 2003 14:36 UTC

this was already asked and answered. search the forums.

UnConeD

15th March 2003 15:44 UTC

You need to make sure both the DM and SSC work in the same camera space. Most superscopes still use the approach of putting an object at (x,y,z) rotated around rx,ry,rz and keep the camera at (0,0,0) looking at the z axis.

A 3D DM however works completely different: the objects are at a fixed position in the world, and the camera moves and rotates around them.

So if you want to synchronize a DM with a SSC you need to make them use the same model. Otherwise the rotations will mean totally different things in the scope and the DM.
It's easiest to alter scopes to match DM behaviour.

Basically if you're good at visualising 3D objects and rotations it should be obvious what you need to do. First you calculate your object regularly, then you add its position to its coordinates (if necessary). Then you need to use the reverse order of rotations in the scope, and use the opposite angles (which basically means flipping the sign on the sines, not the cosines, because cos(a) = cos(-a) ).

If you don't understand why this is necessary, you don't really understand what you're doing with a 3D DM and scope... try visualising what happens when a DM is calculated and a scope is rendered. Remember that rotations always happen around the world axes, which is why the (z,x,y) order of rotations for a DM is the best approach (it's the best equivalent of how a human body looks around).

shreyas_potnis

15th March 2003 17:09 UTC

frankly speaking I understood some part of this ( well I understood the copcept anyway ) . I havent tried this but...i think I will get this right

anubis2003

15th March 2003 17:26 UTC

If you are talking about basic synching, search the forums. There are three basic ways:
Using getosc and getspec
Using counter variables
Creating a pseudo random number generator.

shreyas_potnis

16th March 2003 11:25 UTC

oh, no thats just basic stuff.. :)
ok, i sort of got that right. when the ssc has postion as (0,0,0) and sin(rx,ry and rz) is negative, it works. but as soon as I change its position, the preset looks ugly

UnConeD

16th March 2003 14:34 UTC

Ok that's two people who have suggested a forum search because they think it's about regular synching. Please READ the question asked.

Jaheckelsafar

16th March 2003 14:49 UTC

There was a thread by jheriko about more advnced synching a coupe of months ago in the main forum I think,