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uberzev
not lyftzev
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Source: 50% grey from Assemble HLS.
A threashold setting of 50 results in black. Now type in 49.999. It will then round up to 50.00 but the result will be white. I understand this as "you can enter three decimals places of precision but we'll only display two of them". That's a bit confusing.
Also IMO a 50 threashold of 50% grey should equal 50% grey.
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| Posted: July 3, 2006 6:37 am |
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byRo
an Englishman in Brazil
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uberzev wrote:
Also IMO a 50 threashold of 50% grey should equal 50% grey. |
I can see your reasoning but, to me anyway, the output can only be black or white and never anything else.
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uberzev wrote:
That's a bit confusing. |
Agreed, (one of) the strong point(s) of FF is the "you-can't-do-anything-wrong" user interface. If the control shows one value but operates on another then that just ain`t right.
However, I think you've turned up a very, very special case in which one thousandth of one percent does make a whole lot of difference.
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uberzev wrote:
I understand this as "you can enter three decimals places of precision but we'll only display two of them". |
I'm still lamenting that the contrast and gamma functions needs an irrational number parameter in order to execute their simplest exact transformation (multiply by 2; square (root)).
So, how many decimal places does FF respect in a control?
If I put in 30.1029995663981 (OK, 30.1023  ) for a square root in the Gamma control will this exact number be saved with the filter - or does it get truncated?
Rô
_________________________________
My favourite question is "Why?".
My second favourite is "Why not?"
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| Posted: July 3, 2006 10:47 am |
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onyXMaster
Filter Forge, Inc.
Posts: 350
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The only place where truncation is taking place is UI. So if UI will pass the untruncated value down, you'll get full 64-bit double precision floating point values both in the rendering pipeline and in the filter XML representation. So the only place to "fix" is the UI display limit.
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| Posted: July 3, 2006 3:10 pm |
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onyXMaster
Filter Forge, Inc.
Posts: 350
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Just as a sidenote -- if the "full precision" UI is implemented (I'll leave the decision on possibility of this to Vladimir), you won't need irrational numbers anyway, just pop up your calculator, calculate your square root of two, PI or whatever and then just paste, I really don't think you need 80-bit precision the FPU is capable of (also 80-bit precision will get rounded to 64-bit very soon when rendering) |
| Posted: July 3, 2006 3:12 pm |
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onyXMaster
Filter Forge, Inc.
Posts: 350
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And no, we're not going to implement a built-in calculator |
| Posted: July 3, 2006 3:13 pm |
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byRo
an Englishman in Brazil
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Thanks for the reply, onyxMaster.
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onyXMaster wrote:
Just as a sidenote -- if the "full precision" UI is implemented (I'll leave the decision on possibility of this to Vladimir), |
While jiggling a slider, I wouldn't want any decimal places at all - just when entering a number.
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onyXMaster wrote:
And no, we're not going to implement a built-in calculator |
Rô _________________________________
My favourite question is "Why?".
My second favourite is "Why not?" |
| Posted: July 3, 2006 4:00 pm |
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Vladimir Golovin
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byRo wrote:
While jiggling a slider, I wouldn't want any decimal places at all - just when entering a number. |
What if the slider ranges from, say, 0 to 2?
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| Posted: July 4, 2006 7:35 am |
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Vladimir Golovin
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byRo wrote:
to me anyway, the output can only be black or white and never anything else. |
Exactly, assuming that you replace "black" or "white" with "Low Color" and "High Color".
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| Posted: July 4, 2006 7:37 am |
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Vladimir Golovin
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byRo wrote:
If the control shows one value but operates on another then that just ain`t right. |
Agreed. We'll look into it.
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| Posted: July 4, 2006 8:25 am |
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uberzev
not lyftzev
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I think we should be able to choose what color 50% grey becomes at 50 threashold.
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| Posted: July 4, 2006 9:48 am |
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Vladimir Golovin
Administrator
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Zev, in the simplest case (when the Smooth parameter is set to zero) Threshold is basically a conditional operator -- it is either True or False, and there's no middle.
But the Smooth parameter can provide that "middle" area -- for example if you want the 50% threashold of 50% grey to be equal 50% grey, set the Smooth parameter to a very small non-zero value, like 0.0001.
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| Posted: July 5, 2006 3:05 am |
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Vladimir Golovin
Administrator
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uberzev wrote:
I think we should be able to choose what color 50% grey becomes at 50 threashold. |
If you want something different from the colors that Threshold provides, plug it into Elevation Gradient and use a 3-Color Gradient to provide that particular color.
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| Posted: July 5, 2006 3:18 am |
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