Here's what I would like to do, although I suspect that it's not
possible under this version of Pov-Ray. BTW has anyone compiled a 'wish
list' of features people would like to see? :)

    What I'd like to do is to create a height field, where each point's
height is the SUM of the heights of 2 or more other height fields at the
corresponding point.

    For example. At point <2,3> the height of Height_Field_1 is 0.3 and at
<2,3> on Height_Field_2 is 0.25. The height at the point <2,3> on the
resulting height field at <2,3> is 0.55.

    Why do this? What I'd like to do is form land masses. While plasma
fractals are wonderful for the creation of RANDOM landscapes, I'd like to
create a 'general outline' height field, and then drape the plasma fractal
over it.

    For example, if Heigh_Field_1 is a cone, and Height_Field_2 is a plasma
fractal, then you have a generally random landscape with a humped 'island'
in the middle, which is still 'rocky' in shape. Add a water plane, and
viola. A realistic island. If I want to add more islands, or alter the shape
of the existing one, I simply alter the 'general outline' height field.

    While I've proposed compositing 2 height fields, I don't see why one
could not 'drape' a plasma fractal height field over objects, either.

    Thoughts anyone?

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Charles Krause wrote:

>     Here's what I would like to do, although I suspect that it's not
> possible under this version of Pov-Ray. BTW has anyone compiled a 'wish
> list' of features people would like to see? :)
>
>     What I'd like to do is to create a height field, where each point's
> height is the SUM of the heights of 2 or more other height fields at the
> corresponding point.
>

[SNIP]

Sounds like you want John P. Beale's HF-Lab, which you can get from:

http://www.best.com/~beale

Bill Bohan
http://www.dhc.net/~bilbohan
--
As many programmers as there are, that's how many ways there are to do it.

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Hi !

For combining heightfields, you will probably find several tools that do that
(as pointed out in another answer-post).

>     While I've proposed compositing 2 height fields, I don't see why one
> could not 'drape' a plasma fractal height field over objects, either.

This would be a feature many people would appreciate. But thinking of it, isn't
it just another description of a displacement map? (Draping a heightfield over
an object I mean) At least a displacement map with only positive (additive)
displacement.
The problem I see with draping a heightfield over an object is that, that a
heightfiled (as a bitmap) is flat, and POV-Ray (at this point) only allows
planar heightfield mapping (you can't map a heightfield on a sphere for example,
like to create moutains and craters on a moon).
So what POV-Ray would need, would be a way to map heightfields to other shapes
than a plane (sphere, cylinder?), and/or a way to define a different mapped
heightfield for different surfaces of the same object (like mapping six
heightfields to the six sides of a cube for example), well, or a real
displacement map implementation, which would practically give the same effect,
with the addition of possible negative (subtractive) displacement too.

Johannes.

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I've already had to do this. In building up various attributes of a
height field, I used Paint Shop Pro. I have version 4.12 and it will
perform image arithmetic including Add, Subtract, Multiply, Divide,
Minimum, Maximum. Filters also allow for other effects. I have used the
Soften image filter to remove height steps and then added it to a
"gravel" height field for the final.

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