## 3d2d problem

### 3d2d problem

Hi All!

the problem with 3d and 2d graphics

i have Rectangle and i need rotate it
i'll do it from the rotation matrix

TForm1::P3d __fastcall TForm1::R(TForm1::P3d thk,double angel)
{
P3d t;
t.x=thk.x*cos(angel)-thk.x*sin(angel)+thk.x;
t.y=thk.y;
t.z=thk.z*sin(angel)+thk.z*cos(angel)+thk.z;
return t;

Quote:}

and then translate it to the 2d by

TForm1::P3d __fastcall TForm1::DD(TForm1::P3d thk,TForm1::P3d c)
{
P3d t;
t.x=c.x+thk.x+thk.z/1.4;
t.y=c.y+thk.y-thk.z/1.4;
t.z=thk.z;
return t;
//c.x and c.y is the center

Quote:}

where P3d is
struct P3d
{
double x,y,z;

Quote:};

and where angel is angle

i v rotate it by the timer
when it begin's at first it stand begear then smaler but a little it rotate
and then it fly away
if need i can give full code

with best regards Arkan.

### 3d2d problem

> Hi All!

> the problem with 3d and 2d graphics

> i have Rectangle and i need rotate it
> i'll do it from the rotation matrix

> TForm1::P3d __fastcall TForm1::R(TForm1::P3d thk,double angel)
> {
>   P3d t;
>   t.x=thk.x*cos(angel)-thk.x*sin(angel)+thk.x;
>   t.y=thk.y;
>   t.z=thk.z*sin(angel)+thk.z*cos(angel)+thk.z;
>   return t;

> }

Sorry, this is no rotation matrix

t.x=thk.x*cos(angel)+thk.z*sin(angel);
t.y=thk.y;
t.z=thk.z*cos(angel)-thk.x*sin(angel);

would be a (positive) rotation about the y-axis.

Regards
Horst

### 3d2d problem

>i v rotate it by the timer
>when it begin's at first it stand begear then smaler but a little it rotate
>and then it fly away

Privet!

If you rotate, translate, rotate, translate, ..., the result is not
the same as if you rotate, rotate, ..., translate, translate, ... .

In mathematics we say rotation and translation do not commute.

### 3d2d problem

ok
can you just wrote how it will be

> >i v rotate it by the timer
> >when it begin's at first it stand begear then smaler but a little it
rotate
> >and then it fly away

> Privet!

> If you rotate, translate, rotate, translate, ..., the result is not
> the same as if you rotate, rotate, ..., translate, translate, ... .

> In mathematics we say rotation and translation do not commute.

### 3d2d problem

> ok
> can you just wrote how it will be

No, he can't, becase "how it will be" depends on what exactly you do.

The usual approach is to express everything as matrices so you can
just multiply those together to get the combined action.

Please see the FAQ of this newsgroup for introductions.
--

Even if all the snow were burnt, ashes would remain.

I'm kind of new to 3ds MAX an i've got some problems using it.
(I've got:3ds Max R1.0, Win 95,Cyrix 166+,32 Megs of Ram,Diamond
Stealth 2000)

First of all,when I launch it it always pops up a dialog box asking me
to connect to the Internet.If I press Cacel it completely locks up.
Who can help me?

Secondly, after using it for a long time ,say 1-2 hours,it goes
bezerk.The buttons change colours,the redrawing becomes slow,
sometimes I can't render(it doesn't disply the result of thr render)
It usually happens if I play the preview too many times(in the
viewport).I have the virtual memory set to 120 Megs.

And now,some questions:what are the IPAS everyone after?
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Where can I find the update to R1.1?(I know where R1.2 is)
How can I assign a reflection map to a boolean object?