You probably recognize my name. This isn't my first plea. :) I was hoping
you'd forget, so that you wouldn't remember those embarrasing goofs I made
in replying to threads. If someone would be so kind as to explain to me
exactly how to use the "Reply to Message" function, I would appreciate it!
You may notice that I'm posting in .newusers now instead of
...advanced-users. :)

So I have another problem. I'll be the first to say the solution's probably
right under my nose, but my eyes don't cross that far.

So here's the issue: I have some splines defined for an animation that
aren't performing as expected (and for no particular reason, so far as I
can see). In this particular scene, I have some skeleton parts modeled that
are scattered around the scene. While the camera pans around the exterior
focussed on the centre of the scene, the bones fly and rotate their way
together in the middle.

I had little trouble defining my first spline (I've only done one since I
figured I would wait to do the other 71 splines until I had one working
right), but it seems like when I animate it, the objects don't follow the
full spline. They come to a stop a little bit from the final destination. I
even discovered this with the camera spline, tho it's not noticeable and of
no consequence in that particular situation.

You can look at my file at
http://www.roboticsresources.com/AsISpoke118b.pov. I've only defined the
skull and left arm splines for starters - they are located at line 23600.

If there's someone who could tell me why this is acting this way, I would
really, really appreciate it! I've been stumped by this problem for quite
some time.

Thanks so much, in advance!!

-Mike

Post a reply to this message

Wasn't it Mike Thorn who wrote:
>You probably recognize my name. This isn't my first plea. :) I was hoping
>you'd forget, so that you wouldn't remember those embarrasing goofs I made
>in replying to threads. If someone would be so kind as to explain to me
>exactly how to use the "Reply to Message" function, I would appreciate it!
>You may notice that I'm posting in .newusers now instead of
>...advanced-users. :)
>
>So I have another problem. I'll be the first to say the solution's probably
>right under my nose, but my eyes don't cross that far.
>
>So here's the issue: I have some splines defined for an animation that
>aren't performing as expected (and for no particular reason, so far as I
>can see). In this particular scene, I have some skeleton parts modeled that
>are scattered around the scene. While the camera pans around the exterior
>focussed on the centre of the scene, the bones fly and rotate their way
>together in the middle.
>
>I had little trouble defining my first spline (I've only done one since I
>figured I would wait to do the other 71 splines until I had one working
>right), but it seems like when I animate it, the objects don't follow the
>full spline. They come to a stop a little bit from the final destination. I
>even discovered this with the camera spline, tho it's not noticeable and of
>no consequence in that particular situation.
>
>You can look at my file at
>http://www.roboticsresources.com/AsISpoke118b.pov. I've only defined the
>skull and left arm splines for starters - they are located at line 23600.
>
>If there's someone who could tell me why this is acting this way, I would
>really, really appreciate it! I've been stumped by this problem for quite
>some time.

I can't seem to access that file. "Server does not exist".

Is it possible that you're using a cubic_spline and have missed the fact
that the end control points lie outside the spline:

   Note: Because of the way cubic_splines are defined: the first and 
   last points are tangents rather than points on the spline, 
   cubic_spline interpolation is only valid between the second and next-
   to-last points. For all other spline types, interpolation is valid 
   from the first point to the last point. For t-values outside the 
   valid range, POV-Ray returns the value of the nearest valid point.

-- 
Mike Williams
Gentleman of Leisure

Post a reply to this message

"Mike Williams" <nos### [at] econymdemoncouk> wrote in message
news:aYtKIBAxmO+AFw### [at] econymdemoncouk...
>
> I can't seem to access that file. "Server does not exist".
>
> Is it possible that you're using a cubic_spline and have missed the fact
> that the end control points lie outside the spline:

Almost. He's using quadratic splines improperly, lacking points. I was about
to send my reply when I saw yours.

Bob H.

Post a reply to this message

"Mike Thorn" <films!@!roboticsresources.com> wrote in message
news:web.40f8903540eaa4d949700cac0@news.povray.org...
> in replying to threads. If someone would be so kind as to explain to me
> exactly how to use the "Reply to Message" function, I would appreciate it!

Hiya Mike, looks like you're using the "webview" of the newsgroups. I don't
use it much, except to search for things there occasionally, but there's a
Post a Reply to this Message (Beta Testing) link at the bottom of each
posted message which I'd guess is supposed to do like it says. :)

> figured I would wait to do the other 71 splines until I had one working
> right), but it seems like when I animate it, the objects don't follow the
> full spline. They come to a stop a little bit from the final destination.

I see that your camera look_at spline is going to need at least 3 points
when using quadratic_spline, 4 if were cubic_spline instead, because each
preceeding point is a control for the next. The following two points get
plotted (inbetween first and last if cubic used) on the spline path
according to that previous point.

For those skeleton parts you used only a single point at value 9, so that
would only be plotted at clock=9 (and I believe <0,0,0> at other clock
values in this case). You'll need to add more points in.

Hope that clears things up.

Bob H.

Post a reply to this message

Mike Williams <nos### [at] econymdemoncouk> wrote:
> I can't seem to access that file. "Server does not exist".

Works for me. Maybe you tried too soon? It took me a minute after I posted
to get it online.

> Is it possible that you're using a cubic_spline and have missed the fact
> that the end control points lie outside the spline:

Like Bob mentioned, I'm using quad splines.

I was under the impression, tho, that I didn't need control points with
quadratic splines. That's what I thought I read in the documentation. I
just happen to have a 2-hour car ride ahead of me today, so I'll re-read it
and try again.

-Mike

Post a reply to this message

Wasn't it Mike Thorn who wrote:
>Mike Williams <nos### [at] econymdemoncouk> wrote:
>> I can't seem to access that file. "Server does not exist".
>
>Works for me. Maybe you tried too soon? It took me a minute after I posted
>to get it online.

Still nothing. The DNS resolves to 207.44.204.85, but there doesn't
appear to be a web server at that address.

-- 
Mike Williams
Gentleman of Leisure

Post a reply to this message