ok I have this hare-brained scheme to make a lightbulb that is etched or "reliefed"
with a height map of the Earth.  After 2 days of experimentation, I am at wit's end.

The lightbulb should be lit, and used to cast a little radiosity light, but I still
want to see the relief of the Earth.

I have tried using bump-maps with variations of bright colors (rgb .75 to rgb 3) and
high ambient (.75 to 3) and I either get what looks like a dull white avocado or it
washes out all white.

Any ideas?

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Some_Yahoo <no### [at] waycom> wrote:
> ok I have this hare-brained scheme to make a lightbulb that is etched
> or "reliefed" with a height map of the Earth.  After 2 days of
> experimentation, I am at wit's end.
>
> The lightbulb should be lit, and used to cast a little radiosity light,
> but I still want to see the relief of the Earth.
>
> I have tried using bump-maps with variations of bright colors (rgb .75 to
> rgb 3) and high ambient (.75 to 3) and I either get what looks like a dull
> white avocado or it washes out all white.

Heh - that's quite a problem indeed: Have you ever stared at an etched light
bulb in real life? And seen anything of the etching? With the bulb *not* being
a genuine dull white avocado? :P


Maybe the best bet would be to make the bulb basically two-colored, using an
ambient < 1.0 for the "continents", and some whopping >> 1.0 for the "oceans";
output to HDR format (or, alternatively, to two standard images, one with
standard brightness and one "tuned down"); and post-process the shot(s) to have
the overexposed parts "bleed" somewhat into the remaining image.


(BTW, for your purposes it doesn't really matter whether you crank up the
pigment or the ambient - both have the same effect on the "light output".
Except that changes to the pigment also affect the "diffuse" component, and
possibly highlights and reflections in case you'd happen to be using metallic,
while changes to the ambient obviously affects the "ambient" component only.)

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clipka wrote:
> Some_Yahoo <no### [at] waycom> wrote:
>> ok I have this hare-brained scheme to make a lightbulb that is etched
>> or "reliefed" with a height map of the Earth.  After 2 days of
>> experimentation, I am at wit's end.
>>
>> The lightbulb should be lit, and used to cast a little radiosity light,
>> but I still want to see the relief of the Earth.
>>
>> I have tried using bump-maps with variations of bright colors (rgb .75 to
>> rgb 3) and high ambient (.75 to 3) and I either get what looks like a dull
>> white avocado or it washes out all white.
> 
> Heh - that's quite a problem indeed: Have you ever stared at an etched light
> bulb in real life? And seen anything of the etching? With the bulb *not* being
> a genuine dull white avocado? :P
> 
> 
> Maybe the best bet would be to make the bulb basically two-colored, using an
> ambient < 1.0 for the "continents", and some whopping >> 1.0 for the "oceans";
> output to HDR format (or, alternatively, to two standard images, one with
> standard brightness and one "tuned down"); and post-process the shot(s) to have
> the overexposed parts "bleed" somewhat into the remaining image.
> 
> 
> (BTW, for your purposes it doesn't really matter whether you crank up the
> pigment or the ambient - both have the same effect on the "light output".
> Except that changes to the pigment also affect the "diffuse" component, and
> possibly highlights and reflections in case you'd happen to be using metallic,
> while changes to the ambient obviously affects the "ambient" component only.)
> 
> 
> 
> 
I went with a felt-marker version.   not totally happy with it but oh well.

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Some Yahoo <no### [at] waycom> wrote:
> I went with a felt-marker version.   not totally happy with it but oh well.

With a higher-res version of the map, and the light being more on the yellow
side, it should turn out quite good already.

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