Hi Ron,
I think you're hitting a float precision limit there, or rather a
limit introduced by the way most (all?) computer graphics software do
filtering operations by sampling a square area. But I'll put a big
question mark on the second assumption since I don't know the
specifics.
If you take a classic gauss curve and apply the same gamma operation
to it, you'll see the low end starting to flatten towards 1. Now, if
you look again after your blur operations and sample in the viewer,
you'll see that the x coordinate at which the pixels turn to full
black (0) is the same on all scanlines. The value right before that is
different on each scanline, so the radial gradient is still there, but
the point where each line reaches 0 is the same. If you push that
enough, though, you're flattening all the low end values towards one,
effectively losing the small differences between them.
The only way I can think of to get around that within your gizmo is to
set a threshold to push some of the very low end values to 0. You
could use a clamp node with the "Clamp To" turned on and set to 0, and
then set your threshold using the "minimum" knob.
Quick example:
set cut_paste_input [stack 0]
version 6.2 v4
push $cut_paste_input
Sparkles {
size 30
motion 200
direction 60
fadeTolerance 152
broken_affected 6.6
broken_start 0.3
broken_holes 0.186
sparks_angle 77
name Sparkles2
selected true
xpos -893
ypos -348
}
Crop {
box {0 0 2048 1556}
name Crop2
selected true
xpos -893
ypos -299
}
Group {
name ExpoBlur1
selected true
xpos -893
ypos -224
addUserKnob {20 ExpoBlur}
addUserKnob {14 size R 0 5}
size 2
addUserKnob {41 strength T Grade160.white}
addUserKnob {41 curve T Grade160.gamma}
addUserKnob {41 black_clamp l "black clamp" T Grade160.black_clamp}
addUserKnob {41 white_clamp l "white clamp" -STARTLINE T Grade160.white_clamp}
addUserKnob {41 crop l "crop to format" T Blur11.crop}
addUserKnob {41 minimum T Clamp1.minimum}
}
Input {
inputs 0
name Input1
xpos 389
ypos -32
}
Dot {
name Dot328
xpos 423
ypos -4
}
set N4ba6c50 [stack 0]
add_layer {rgba rgba.beta}
Blur {
size {{parent.size**7} {parent.size**7}}
crop {{parent.Blur11.crop}}
name Blur17
xpos 714
ypos 100
}
push $N4ba6c50
Blur {
size {{parent.size**6} {parent.size**6}}
crop {{parent.Blur11.crop}}
name Blur16
xpos 589
ypos 96
}
push $N4ba6c50
Blur {
size {{parent.size**5} {parent.size**5}}
crop {{parent.Blur11.crop}}
name Blur15
xpos 499
ypos 104
}
push $N4ba6c50
Blur {
size {{parent.size**4} {parent.size**4}}
crop {{parent.Blur11.crop}}
name Blur14
xpos 389
ypos 106
}
push $N4ba6c50
Blur {
size {{parent.size**3} {parent.size**3}}
crop {{parent.Blur11.crop}}
name Blur13
xpos 287
ypos 108
}
push 0
push $N4ba6c50
Blur {
size {{parent.size*2} {parent.size*2}}
crop {{parent.Blur11.crop}}
name Blur12
xpos 174
ypos 108
}
push $N4ba6c50
Blur {
size {{parent.size} {parent.size}}
name Blur11
xpos 53
ypos 115
}
Merge2 {
inputs 7+1
operation plus
name Merge243
xpos 389
ypos 233
}
Clamp {
minimum 4e-05
maximum_enable false
MinClampTo_enable true
name Clamp1
xpos 389
ypos 278
}
set N74959c0 [stack 0]
Grade {
channels rgba
white 1.02
gamma 11
white_clamp true
name Grade160
xpos 389
ypos 358
}
Output {
name Output1
xpos 389
ypos 438
}
push $N74959c0
Viewer {
input_process false
name Viewer1
xpos 570
ypos 426
}
end_group
On Wed, Jul 20, 2011 at 10:27 AM, Ron Ganbar <[email protected]> wrote:
> Is the gamma (curve) all the way up on 5 and size on 2 and you're not
> getting a square?
>
>
> Ron Ganbar
> email: [email protected]
> tel: +44 (0)7968 007 309 [UK]
> +972 (0)54 255 9765 [Israel]
> url: http://ronganbar.wordpress.com/
>
>
> On 20 July 2011 18:19, Randy Little <[email protected]> wrote:
>>
>> did you try hooking and unhooking or leaving hooked a a black constant.
>> Its 2 am I don't know what buttons I pushed to make it work. SORRY. BUT
>> Randy S. Little
>> http://www.rslittle.com
>>
>>
>>
>>
>> On Thu, Jul 21, 2011 at 01:16, Ron Ganbar <[email protected]> wrote:
>>>
>>> Hi Randy,
>>> Still wrong on my end... :-(
>>> Played with Blur11 - didn't seem to make any difference.
>>> Thanks for trying.
>>>
>>> Ron Ganbar
>>> email: [email protected]
>>> tel: +44 (0)7968 007 309 [UK]
>>> +972 (0)54 255 9765 [Israel]
>>> url: http://ronganbar.wordpress.com/
>>>
>>>
>>> On 20 July 2011 18:12, Randy Little <[email protected]> wrote:
>>>>
>>>> Merry Xmas its fixed. The weird thing is that fixing was to turn off
>>>> crop to format in the blur11 then turn it back on. ????? So I don't
>>>> know.
>>>> strange. maybe it was holding onto the format from pre crop some how for
>>>> whatever reason.
>>>> set cut_paste_input [stack 0]
>>>> version 6.2 v3
>>>> push $cut_paste_input
>>>> Sparkles {
>>>> size 30
>>>> motion 200
>>>> direction 60
>>>> fadeTolerance 152
>>>> broken_affected 6.6
>>>> broken_start 0.3
>>>> broken_holes 0.186
>>>> sparks_angle 77
>>>> name Sparkles1
>>>> selected true
>>>> xpos -111
>>>> ypos -205
>>>> }
>>>> Crop {
>>>> box {0 0 2048 1556}
>>>> name Crop4
>>>> selected true
>>>> xpos -106
>>>> ypos -157
>>>> }
>>>> Group {
>>>> name ExpoBlur2
>>>> selected true
>>>> xpos -106
>>>> ypos -103
>>>> addUserKnob {20 ExpoBlur}
>>>> addUserKnob {14 size R 0 5}
>>>> size 0.2
>>>> addUserKnob {41 strength T Grade160.white}
>>>> addUserKnob {41 curve T Grade160.gamma}
>>>> addUserKnob {41 black_clamp l "black clamp" T Grade160.black_clamp}
>>>> addUserKnob {41 white_clamp l "white clamp" -STARTLINE T
>>>> Grade160.white_clamp}
>>>> addUserKnob {41 crop l "crop to format" T Blur11.crop}
>>>> }
>>>> Input {
>>>> inputs 0
>>>> name Input1
>>>> xpos 389
>>>> ypos -32
>>>> }
>>>> Dot {
>>>> name Dot328
>>>> xpos 423
>>>> ypos -4
>>>> }
>>>> set N1c441b60 [stack 0]
>>>> add_layer {rgba rgba.beta}
>>>> Blur {
>>>> size {{parent.size**7} {parent.size**7}}
>>>> crop {{parent.Blur11.crop}}
>>>> name Blur17
>>>> xpos 714
>>>> ypos 100
>>>> }
>>>> push $N1c441b60
>>>> Blur {
>>>> size {{parent.size**6} {parent.size**6}}
>>>> crop {{parent.Blur11.crop}}
>>>> name Blur16
>>>> xpos 589
>>>> ypos 96
>>>> }
>>>> push $N1c441b60
>>>> Blur {
>>>> size {{parent.size**5} {parent.size**5}}
>>>> crop {{parent.Blur11.crop}}
>>>> name Blur15
>>>> xpos 499
>>>> ypos 104
>>>> }
>>>> push $N1c441b60
>>>> Blur {
>>>> size {{parent.size**4} {parent.size**4}}
>>>> crop {{parent.Blur11.crop}}
>>>> name Blur14
>>>> xpos 389
>>>> ypos 106
>>>> }
>>>> push $N1c441b60
>>>> Blur {
>>>> size {{parent.size**3} {parent.size**3}}
>>>> crop {{parent.Blur11.crop}}
>>>> name Blur13
>>>> xpos 287
>>>> ypos 108
>>>> }
>>>> push 0
>>>> push $N1c441b60
>>>> Blur {
>>>> size {{parent.size*2} {parent.size*2}}
>>>> crop {{parent.Blur11.crop}}
>>>> name Blur12
>>>> xpos 174
>>>> ypos 108
>>>> }
>>>> push $N1c441b60
>>>> Blur {
>>>> size {{parent.size} {parent.size}}
>>>> name Blur11
>>>> xpos 53
>>>> ypos 115
>>>> }
>>>> Merge2 {
>>>> inputs 7+1
>>>> operation plus
>>>> name Merge243
>>>> xpos 389
>>>> ypos 232
>>>> }
>>>> set N1c474b50 [stack 0]
>>>> Grade {
>>>> channels rgba
>>>> white 1.02
>>>> gamma 0.435
>>>> white_clamp true
>>>> name Grade160
>>>> xpos 389
>>>> ypos 311
>>>> }
>>>> Output {
>>>> name Output1
>>>> xpos 389
>>>> ypos 438
>>>> }
>>>> push $N1c474b50
>>>> Viewer {
>>>> input_process false
>>>> name Viewer1
>>>> selected true
>>>> xpos 570
>>>> ypos 426
>>>> }
>>>> end_group
>>>> Randy S. Little
>>>> http://www.rslittle.com
>>>>
>>>>
>>>>
>>>>
>>>> On Thu, Jul 21, 2011 at 00:52, Ron Ganbar <[email protected]> wrote:
>>>>>
>>>>> set cut_paste_input [stack 0]
>>>>> version 6.2 v4
>>>>> push $cut_paste_input
>>>>> Sparkles {
>>>>> size 30
>>>>> name Sparkles1
>>>>> selected true
>>>>> xpos -304
>>>>> ypos 3346
>>>>> }
>>>>> Crop {
>>>>> box {0 0 2048 1556}
>>>>> name Crop4
>>>>> selected true
>>>>> xpos -304
>>>>> ypos 3374
>>>>> }
>>>>> Group {
>>>>> name ExpoBlur2
>>>>> selected true
>>>>> xpos -304
>>>>> ypos 3422
>>>>> addUserKnob {20 ExpoBlur}
>>>>> addUserKnob {14 size R 0 5}
>>>>> size 2
>>>>> addUserKnob {41 strength T Grade160.white}
>>>>> addUserKnob {41 curve T Grade160.gamma}
>>>>> addUserKnob {41 black_clamp l "black clamp" T Grade160.black_clamp}
>>>>> addUserKnob {41 white_clamp l "white clamp" -STARTLINE T
>>>>> Grade160.white_clamp}
>>>>> addUserKnob {41 crop l "crop to format" T Blur11.crop}
>>>>> }
>>>>> Input {
>>>>> inputs 0
>>>>> name Input1
>>>>> xpos 389
>>>>> ypos -32
>>>>> }
>>>>> Dot {
>>>>> name Dot328
>>>>> xpos 423
>>>>> ypos -4
>>>>> }
>>>>> set Nbb6ed990 [stack 0]
>>>>> add_layer {rgba rgba.beta}
>>>>> Blur {
>>>>> size {{parent.size**7 i} {parent.size**7 i}}
>>>>> crop {{parent.Blur11.crop i}}
>>>>> name Blur17
>>>>> xpos 714
>>>>> ypos 100
>>>>> }
>>>>> push $Nbb6ed990
>>>>> Blur {
>>>>> size {{parent.size**6 i} {parent.size**6 i}}
>>>>> crop {{parent.Blur11.crop i}}
>>>>> name Blur16
>>>>> xpos 606
>>>>> ypos 103
>>>>> }
>>>>> push $Nbb6ed990
>>>>> Blur {
>>>>> size {{parent.size**5 i} {parent.size**5 i}}
>>>>> crop {{parent.Blur11.crop i}}
>>>>> name Blur15
>>>>> xpos 499
>>>>> ypos 104
>>>>> }
>>>>> push $Nbb6ed990
>>>>> Blur {
>>>>> size {{parent.size**4 i} {parent.size**4 i}}
>>>>> crop {{parent.Blur11.crop i}}
>>>>> name Blur14
>>>>> xpos 389
>>>>> ypos 106
>>>>> }
>>>>> push $Nbb6ed990
>>>>> Blur {
>>>>> size {{parent.size**3 i} {parent.size**3 i}}
>>>>> crop {{parent.Blur11.crop i}}
>>>>> name Blur13
>>>>> xpos 287
>>>>> ypos 108
>>>>> }
>>>>> push 0
>>>>> push $Nbb6ed990
>>>>> Blur {
>>>>> size {{parent.size*2 i} {parent.size*2 i}}
>>>>> crop {{parent.Blur11.crop i}}
>>>>> name Blur12
>>>>> xpos 174
>>>>> ypos 108
>>>>> }
>>>>> push $Nbb6ed990
>>>>> Blur {
>>>>> size {{parent.size} {parent.size}}
>>>>> name Blur11
>>>>> xpos 53
>>>>> ypos 111
>>>>> }
>>>>> Merge2 {
>>>>> inputs 7+1
>>>>> operation plus
>>>>> name Merge243
>>>>> xpos 389
>>>>> ypos 283
>>>>> }
>>>>> Grade {
>>>>> channels rgba
>>>>> gamma 6
>>>>> white_clamp true
>>>>> name Grade160
>>>>> xpos 389
>>>>> ypos 311
>>>>> }
>>>>> set Nc73fb7f0 [stack 0]
>>>>> Viewer {
>>>>> viewerProcess SHOWLinAsFilm3D
>>>>> input_process false
>>>>> name Viewer1
>>>>> xpos 570
>>>>> ypos 426
>>>>> }
>>>>> push $Nc73fb7f0
>>>>> Output {
>>>>> name Output1
>>>>> xpos 389
>>>>> ypos 438
>>>>> }
>>>>> end_group
>>>>
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>>
>>
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>
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