## line - volume intersection ...and texture mapping

### line - volume intersection ...and texture mapping

Hello,

I'm looking a way to get the x,y,z coordinates of the intersection point
of a line through a volume. The line is defined by two points, one is
the origin.

One volume is a conic

_______
\_______/
/         \
/...........\
\___________/

Sorry it is not well drawn. It's a cone cut with paralle surfaces and
othogonal to the central axe. The axe is always vertical in my case.
So we have r1 and r2 for the two radius and h the height of the cone.

Volume 2 is obtained by a revolution around a vertical axis of a
polyline. The polyline is defined as a sequence of points.

I also need the transformation to get the u,v values for these volumes.
Note that mapping on the cone should not strech the texture.

### line - volume intersection ...and texture mapping

> I'm looking a way to get the x,y,z coordinates of the intersection point
> of a line through a volume. The line is defined by two points, one is
> the origin.

> One volume is a conic

>          _______
>    \_______/
>        /         \
>       /...........\
>       \___________/

> Sorry it is not well drawn. It's a cone cut with paralle surfaces and
> othogonal to the central axe. The axe is always vertical in my case.
> So we have r1 and r2 for the two radius and h the height of the cone.

> Volume 2 is obtained by a revolution around a vertical axis of a
> polyline. The polyline is defined as a sequence of points.

problem; as I recall, he transformed the surface of rotation into a
plane and intersected with a curved ray! I can't dig up the reference
right now; it seems to be before 1985 ('84?).

<snip>
--
-Stephen H. Westin

The information and opinions in this message are mine, not Ford's.

Hi,

A question which I hope some kind soul can solve for me:

I'm doing a project on volume rendering using ray-casting. In the program, the view pane is rotated
about the centre of the volume instead of rotating the whole volume. Given the vector equation of
the line, how do I compute the points at which the ray enter and leave the volume?

Help is greatly appreciated.

Regards,
ohm

8. TGL-3D