 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
I just started to try out my 3.1 scenes with the new 3.5 Version.
nice.
After reading the documentation I have a couple of questions:
It says after adding inside_vector the mesh has an inside.
Then it goes on with for example using +z as the direction I state
inside_vector <0, 0, 1>
OK: Here it goes
1. Why would I want to use +z???
3.How does the shape of my mesh influence the direction of the
inside_vector I should use???
principle of that vector and how to chose a vector for a mesh (or if
Help please.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Thu, 5 Sep 2002 13:42:24 EDT, "Ernst Fritsch" <ern### [at] cityweb de>
wrote:
IIRC You have to point any point inside mesh to specify which side of mesh is
defined as inside. inside_vector is not direction, it is a point.
ABX
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Ernst Fritsch wrote:
>
> [...]
>
> principle of that vector and how to chose a vector for a mesh (or if
I think the docs are quite clear about it. To determine whether a point
is inside or outside the mesh POV-Ray shoots a ray in direction of
'inside_vector' and counts the intersections.
What this means: If the mesh is perfectly closed the inside_vector won't
influence the render result at all. It may be though that speed is
influenced but this is a more complicated matter. If the mesh is not
perfectly closed it may be possible to use it in CSG anyway if you choose
the correct inside_vector.
Christoph
--
POV-Ray tutorials, IsoWood include,
TransSkin and more: http://www.tu-bs.de/~y0013390/
Last updated 13 Aug. 2002 _____./\/^>_*_<^\/\.______
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Christoph Hormann wrote:
>
>I think the docs are quite clear about it. To determine whether a point
>is inside or outside the mesh POV-Ray shoots a ray in direction of
>'inside_vector' and counts the intersections.
>
What you wrote there makes sense but:
In my documentation it says "To determine if a point is inside a
triangle mesh, POV-Ray shoots a ray from the point (wich one,
the one inside or outside the mesh or the inside_vector??) in some arbitrary
direction. If ...." and so on. It tells me that I can specify the direction
of that vector but it does not tell me on what basis.
If it would just say "As inside_vector choose any point inside the mesh."
it would make sense to me (provided that is really what the documentation
means).
By the way that was the first time in the last couple of years that I had
serious trouble with the POV-Ray documentation. So while I still think that
By the way Thanks to ABX
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
> In my documentation it says "To determine if a point is inside a
> triangle mesh, POV-Ray shoots a ray from the point (wich one,
> the one inside or outside the mesh or the inside_vector??) in some arbitrary
> direction. If ...." and so on. It tells me that I can specify the direction
> of that vector but it does not tell me on what basis.
it shoots a ray from the point that has to be checked in the direction of
inside_vector.
> If it would just say "As inside_vector choose any point inside the mesh."
> it would make sense to me (provided that is really what the documentation
> means).
It isn't if I understand you correctly...
And if I'm not mistaken :)
cu!
--
camera{location-z*3}#macro G(b,e)b+(e-b)*(C/50)#end#macro L(b,e,k,l)#local C=0
;#while(C<50)sphere{G(b,e),.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1
;#end#end L(y-x,y,x,x+y)L(y,-x-y,x+y,y)L(-x-y,-y,y,y+z)L(-y,y,y+z,x+y)L(0,x+y,
<.5,1,.5>,x)L(0,x-y,<.5,1,.5>,x) // ZK http://www.povplace.be.tf
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Ernst Fritsch wrote:
>
> [...]
>
> In my documentation it says "To determine if a point is inside a
> triangle mesh, POV-Ray shoots a ray from the point (wich one,
> the one inside or outside the mesh or the inside_vector??) in some arbitrary
> direction. If ...." and so on. It tells me that I can specify the direction
> of that vector but it does not tell me on what basis.
>
I don't understand what's ambiguous about "To determine if a point is
inside a triangle mesh, POV-Ray shoots a ray from the point..."
Christoph
--
POV-Ray tutorials, IsoWood include,
TransSkin and more: http://www.tu-bs.de/~y0013390/
Last updated 13 Aug. 2002 _____./\/^>_*_<^\/\.______
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
> I don't understand what's ambiguous about "To determine if a point is
> inside a triangle mesh, POV-Ray shoots a ray from the point..."
He's just saying that, while it explains how the inside_vector is used, it
doesn't explain how to choose the inside_vector.
Now, if you can understand the explanation of how it's used, then it's clear
how to choose it. But I agree that a statement such as "choose a point
inside the mesh for inside_vector" would be appropriate for less
mathematically inclined users, if such a statement isn't already in there.
- Slime
[ http://www.slimeland.com/ ]
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Slime wrote:
>
> [...]
> Now, if you can understand the explanation of how it's used, then it's clear
> how to choose it. But I agree that a statement such as "choose a point
> inside the mesh for inside_vector" would be appropriate for less
> mathematically inclined users, if such a statement isn't already in there.
But that's wrong, the inside_vector is defining the direction for making
the insideness test. With well made meshes you can use *any* vector for
this purpose.
Christoph
--
POV-Ray tutorials, IsoWood include,
TransSkin and more: http://www.tu-bs.de/~y0013390/
Last updated 13 Aug. 2002 _____./\/^>_*_<^\/\.______
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
ABX <abx### [at] abxartpl> wrote:
> IIRC You have to point any point inside mesh to specify which side of mesh is
> defined as inside. inside_vector is not direction, it is a point.
No, that's not it. (How could POV-Ray determine if some point is inside
the mesh or not using the information that another point is inside it?)
--
#macro N(D)#if(D>99)cylinder{M()#local D=div(D,104);M().5,2pigment{rgb M()}}
N(D)#end#end#macro M()<mod(D,13)-6mod(div(D,13)8)-3,10>#end blob{
N(11117333955)N(4254934330)N(3900569407)N(7382340)N(3358)N(970)}// - Warp -
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Christoph Hormann <chr### [at] gmxde> wrote:
> With well made meshes you can use *any* vector for
> this purpose.
I think that the idea is that you should preferably choose a vector which
is not parallel to any of the triangles because those triangles might cause
some problems. AFAIK.
--
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
