 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
can someone explain to me some of the notation in the pov-ray help files. I
looked in the help for how to make a prism and it gave this:
PRISM:
{ [PRISM_ITEMS] F_HEIGHT1, F_HEIGHT2, I_NUM_POINTS, POINT_LIST [open]
[PRISM_MODIFIERS] }
PRISM_ITEMS:
[PRISM_SPLINE_TYPE] & [PRISM_SWEEP_TYPE]
PRISM_SPLINE_TYPE:
linear_spline | quadratic_spline | cubic_spline | bezier_spline
PRISM_SWEEP_TYPE:
linear_sweep | conic_sweep
PRISM_MODIFIERS:
[sturm [BOOL]] & [OBJECT_MODIFIERS]
what do the F/I and in other areas V terms mean? I can't work out how to do a
prism from this information
Please help
Thanks
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
colaroid schrieb:
> can someone explain to me some of the notation in the pov-ray help files. I
> looked in the help for how to make a prism and it gave this:
>
> PRISM:
> { [PRISM_ITEMS] F_HEIGHT1, F_HEIGHT2, I_NUM_POINTS, POINT_LIST [open]
> [PRISM_MODIFIERS] }
> PRISM_ITEMS:
> [PRISM_SPLINE_TYPE] & [PRISM_SWEEP_TYPE]
> PRISM_SPLINE_TYPE:
> linear_spline | quadratic_spline | cubic_spline | bezier_spline
> PRISM_SWEEP_TYPE:
> linear_sweep | conic_sweep
> PRISM_MODIFIERS:
> [sturm [BOOL]] & [OBJECT_MODIFIERS]
>
> what do the F/I and in other areas V terms mean? I can't work out how to do a
> prism from this information
F_*, I_* and V_* indicate that the parameter is to be a floating-point
value, an integer value, or a vector value, respectively.
"[FOO]" means that the respective parameter or parameter group is optional.
"FOO | BAR" means that you must specify either "FOO" or "BAR".
I'm not sure off the top of my hat whether "FOO & BAR" denotes that you
must specify "FOO" followed by "BAR", or whether you can specify them in
any order. I think it's the former.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
clipka wrote:
> "[FOO]" means that the respective parameter or parameter group is optional.
>
> "FOO | BAR" means that you must specify either "FOO" or "BAR".
In case you have not heard the terms FOO and BAR before
http://en.wikipedia.org/wiki/Foobar
--
Best Regards,
Stephen
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
> can someone explain to me some of the notation in the pov-ray help files. I
> looked in the help for how to make a prism and it gave this:
>
> PRISM:
> { [PRISM_ITEMS] F_HEIGHT1, F_HEIGHT2, I_NUM_POINTS, POINT_LIST [open]
> [PRISM_MODIFIERS] }
F_HEIGHT1, F_HEIGHT2 determine the vertical extent of the prism. They
must be different. Their use is very simple for linear_sweep. It can be
tricky when you use a conical_sweep (normaly, you also need to use some
scaling).
I_NUM_POINTS is the number of points needed to define the shape of the
prism. It includes the actual points plus any controll points.
POINT_LIST is a list of the actual 2D doordinates of all the points
defining the shape of the prism. It MUST match the value of I_NUM_POINTS.
> PRISM_ITEMS:
> [PRISM_SPLINE_TYPE] & [PRISM_SWEEP_TYPE]
Those are optional parameters with default values.
> PRISM_SPLINE_TYPE:
> linear_spline | quadratic_spline | cubic_spline | bezier_spline
linear_spline means that the points are connected by straight lines. NO
controll point. (default spline type used if not defined)
All others can have curved shapes and need at least 2 controll points.
bezier_spline use: point, control_point, control_point, point,
control_point,....(2 control points between each actual points pair)
> PRISM_SWEEP_TYPE:
> linear_sweep | conic_sweep
linear = sides that are parallel (default value that will be used if you
don't provide that parameter)
conic = sides that converge to a single point.
You must use one or the other, but never both.
> PRISM_MODIFIERS:
> [sturm [BOOL]] & [OBJECT_MODIFIERS]
Optional parameters.
strum use an alternate, more precise but slower, algorythm to trace the
prism. If strum is absent, it's means "strun off". It's presence alone
means "strum on".
The object modifiers are things like rotation, scalling and
translations. Can also include any pigment, texture or material.
>
> what do the F/I and in other areas V terms mean? I can't work out how to do a
> prism from this information
>
> Please help
>
> Thanks
>
>
"F" is for a float numerical value: 1.2345, pi, 1/3, sin(0.1), ...
"I" is for an integer numerical value: 1
"V" is for a vector like: <1,2>, <1,2,3>,... If needed, a single float
or integer can be used if you want a vector where all elements have the
same value. In that case, the value provided will be promoted to a
vector. 1 can become <1,1,1>
A simple prism:
prism{0,1, 4 0,<1,1>,<1,0>,0}
Create a triangular prism one unit high. The sides are straight and
vertical.
Alain
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Alain <aze### [at] qwerty org> wrote:
> > can someone explain to me some of the notation in the pov-ray help files. I
> > looked in the help for how to make a prism and it gave this:
> >
> > PRISM:
> > { [PRISM_ITEMS] F_HEIGHT1, F_HEIGHT2, I_NUM_POINTS, POINT_LIST [open]
> > [PRISM_MODIFIERS] }
> F_HEIGHT1, F_HEIGHT2 determine the vertical extent of the prism. They
> must be different. Their use is very simple for linear_sweep. It can be
> tricky when you use a conical_sweep (normaly, you also need to use some
> scaling).
> I_NUM_POINTS is the number of points needed to define the shape of the
> prism. It includes the actual points plus any controll points.
> POINT_LIST is a list of the actual 2D doordinates of all the points
> defining the shape of the prism. It MUST match the value of I_NUM_POINTS.
>
> > PRISM_ITEMS:
> > [PRISM_SPLINE_TYPE] & [PRISM_SWEEP_TYPE]
> Those are optional parameters with default values.
>
> > PRISM_SPLINE_TYPE:
> > linear_spline | quadratic_spline | cubic_spline | bezier_spline
> linear_spline means that the points are connected by straight lines. NO
> controll point. (default spline type used if not defined)
> All others can have curved shapes and need at least 2 controll points.
> bezier_spline use: point, control_point, control_point, point,
> control_point,....(2 control points between each actual points pair)
>
> > PRISM_SWEEP_TYPE:
> > linear_sweep | conic_sweep
> linear = sides that are parallel (default value that will be used if you
> don't provide that parameter)
> conic = sides that converge to a single point.
> You must use one or the other, but never both.
>
> > PRISM_MODIFIERS:
> > [sturm [BOOL]] & [OBJECT_MODIFIERS]
> Optional parameters.
> strum use an alternate, more precise but slower, algorythm to trace the
> prism. If strum is absent, it's means "strun off". It's presence alone
> means "strum on".
> The object modifiers are things like rotation, scalling and
> translations. Can also include any pigment, texture or material.
>
> >
> > what do the F/I and in other areas V terms mean? I can't work out how to do a
> > prism from this information
> >
> > Please help
> >
> > Thanks
> >
> >
> "F" is for a float numerical value: 1.2345, pi, 1/3, sin(0.1), ...
> "I" is for an integer numerical value: 1
> "V" is for a vector like: <1,2>, <1,2,3>,... If needed, a single float
> or integer can be used if you want a vector where all elements have the
> same value. In that case, the value provided will be promoted to a
> vector. 1 can become <1,1,1>
>
> A simple prism:
> prism{0,1, 4 0,<1,1>,<1,0>,0}
> Create a triangular prism one unit high. The sides are straight and
> vertical.
>
>
> Alain
Thankyou for your help-thats brilliant.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
|
|
