Hi
I need help convert HSV to RGB. Is it any fast method in maxscript to do that, because unfortunately i can’t find nothing or I need use some key code for this transformation, because i have found few keys code from python or java but i am not understand very well to those languages . So has anybody idea how i can solve my problem :)? Has anybody this conversion already coded :)?
cheers
So if will be somebody else solve this problem in future here is my solution
HSV_col = [38,30,250] -- input HSV
fn HSVtoRGB =
(
h = hsv_col[1] / 255 as float
s = hsv_col[2] / 255 as float
v = hsv_col[3] / 255 as float
if ( S == 0 ) then
(
R = V * 255
G = V * 255
B = V * 255
)
else
(
var_h = H * 6
if ( var_h == 6 ) do ( var_h = 0 )
var_i = (( var_h ) as integer)
var_1 = V * ( 1 - S )
var_2 = V * ( 1 - S * ( var_h - var_i ) )
var_3 = V * ( 1 - S * ( 1 - ( var_h - var_i ) ) )
)
if ( var_i == 0 ) then
(
var_r = V
var_g = var_3
var_b = var_1
)
else
(
if ( var_i == 1 ) then
(
var_r = var_2
var_g = V
var_b = var_1
)
else
(
if ( var_i == 2 ) then
(
var_r = var_1
var_g = V
var_b = var_3
)
else
(
if ( var_i == 3 ) then
(
var_r = var_1
var_g = var_2
var_b = V
)
else
(
if ( var_i == 4 ) then
(
var_r = var_3
var_g = var_1
var_b = V
)
else
(
var_r = V
var_g = var_1
var_b = var_2
)
)
)
)
)
R = ceil (var_r * 255)
G = ceil (var_g * 255)
B = ceil (var_b * 255)
RGB_col = [R,G,B] -- HSV converted into RGB
)
HSVtoRGB ()
MAX color value has h, s, and v properties. If you set them with HSV, does it not return right numbers in R,G, and B?
Hi DenisT
I though the same but from some reason I don’t understand why it doesn’t work this way which is for me curious, or maybe i did something wrong, but i am almost sure I tested it correctly. But if anybody find I am wrong I am happy to see why, because my solution is not very smart and i just rewrite some code which was written for C+
I didn’t have a chance to check it yesterday, but as I thought there is no problem to convert HSV to RGB using of color value:
fn HSV_to_RGB hsv =
(
rgb = black -- it might be any color
rgb.v = hsv.z
rgb.s = hsv.y
rgb.h = hsv.x
rgb as point3
)
HSV_to_RGB [38,30,250]
the order of the setting of HSV is important. It has to be V, S, and H.
Thanks Denis. I am happy this works definitely better than my. I just don’t fully understand what you have done . For example how you can input anything into rgb . From what i know it is read only variable. So i am little confused
probably my local variable “rgb” was confused you. It might be any name. Change “rgb” to “col” if you want. It’s just a local name for color variable.
When I updated the Coolpicker color picker years ago, there was c++ code that would do that for both 8 bit color values, and for floating point values as well. It is currently open source of course, and can be found on maxplugins.de I believe.
Yup, Chris is right, you can get the latest version of the source code here:
http://source.maxplugins.de/colorpicker/CoolPicker_v2.3.1_source.zip
Dave
Here’s my old model translated directly from the pegtop delphi and adobe blendmode documents:
fn vToC valueVal = --accepts a point3 value, returns an equivalent color value
(
return [(valueVal.x*255 as integer), (valueVal.y*255 as integer), (valueVal.z*255 as integer)] as color
)
fn cToV colorVal = --accepts a color value, returns an equivalent point3 value
(
tempVal = colorVal as point3
return [(tempVal.x/255), (tempVal.y/255), (tempVal.z/255)]
)
fn HSVtoRGB hsvVal = --accepts an HSV model point3 value, returns an equivalent RGB model point3 value
(
if hsvVal.y == 0 then
(
return vToC [hsvVal.z, hsvVal.z, hsvVal.z]
)
else
(
testH = hsvVal.x*6
if testH == 6 then
(
testH = 0
)
var_i = testH as int
var_1 = hsvVal.z*(1-hsvVal.y)
var_2 = hsvVal.z*(1-hsvVal.y*(testH-var_i))
var_3 = hsvVal.z*(1-hsvVal.y*(1-(testH-var_i)))
case var_i of
(
0: return [hsvVal.z, var_3, var_1]
1: return [var_2, hsvVal.z, var_1]
2: return [var_1, hsvVal.z, var_3]
3: return [var_1, var_2, hsvVal.z]
4: return [var_3, var_1, hsvVal.z]
default: return [hsvVal.z, var_1, var_2]
)
)
)
This accepts and returns scaled point3 float values from 0-1, so some conversions may be necessary depending on what you’re interfacing it with.