now make move together yellow.x = green.x and yellow.y = green.y over a white background and voila
Question – Code [SOLVED] blend colours as paint blend
Here when I blend the two circles : cyan + yellow = green (what I am looking for)
BUT it is not working as paint blend with other colours.
I would like to have a unique method to have the blends dealing with paint that is :
blue (not cyan) + yellow = green
red + blue = purple
red + yellow = orange
white or black background
thanks for helping me finding a neat solution to this problem
(I have taken some time on gpu_set_blendmode_ext function and this excellent article https://www.yoyogames.com/blog/57/explaining-blend-modes-part-2 but my conclusion is that it is not possible this way. )
Last edited by a moderator: Jun 11, 2017
yoyowan
Guest
try to explain the mathematical way :
for example cyan + yellow = green
cyan is RGB (0,255,255) and yellow is RGB (255,255,0) now converted to 0 – 1 it gives :
cyan (0,1,1) and yellow (1,1,0)
I use gpu_set_blendmode_ext(bm_dest_colour,bm_zero) that is
(Rs,Gs,Bs,As)*(Rd,Gd,Bd,Ad)+(Rd,Gd,Bd,Ad)*(0,0,0,0) = (Rs,Gs,Bs,As)*(Rd,Gd,Bd,Ad)
Source color * dest color + dest color * zero = source color * dest color
so (0,1,1) * (1,1,0) = (0,1,0) GREEN
if I keep this mode and try red + blue :
(1,0,0) * (0,0,1) = (0,0,0) BLACK
yoyowan
Guest
an image of what I am trying to do :
Last edited by a moderator: Jun 11, 2017
Member
Is it not subtractive blending that you want?
Guest
Is it not subtractive blending that you want?
kind of.
In pure substractive blending cyan + yellow = green
I would like blue + yellow = green
In pure substractive blending red + blue = black
I would like red + blue = purple
Last edited by a moderator: Jun 11, 2017
Member
bm_subtract is one of the basic blend modes.
Guest
Thanks sp202 but I have clarified a little bit see :
kind of.
In pure substractive blending cyan + yellow = green
I would like blue + yellow = green
In pure substractive blending red + blue = black
I would like red + blue = purple
Blending blue-hour foreground with night sky timelapse? Possible?
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GBakker
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Posts: 10
Threads: 3
Joined: Apr 2016
#1 GBakker 2022-09-20, 03:18
For a still photo, my standard process is to take a blue-hour photo of the foreground and then blend it into the multiple image stacked starry sky photo. The purpose obviously is to get good foreground detail with minimal noise.
How do I accomplish something similar for a night sky timelapse (without a tracker)? I want a night sky timelapse with a high quality foreground, and my attempts so far have been poor.
I can’t extend the exposure time because I’ll get unwanted star trails. (or, do star trails even matter with a timelapse? — I’ve never tried that) A higher ISO would provide a brighter exposure (with possibly more noise) but could blow out the stars themselves. I’m already wide open with my aperture.
I’m stumped. Is the only answer a tracker?
My equipment:
Sony A7iv. Sony G 20mm 1.8.
Gary[size=small] [size=x-small][size=xx-small](Sony A6300 shooter)[/size][/size][/size]
Gunther
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Posts: 13,667
Threads: 179
Joined: Feb 2011
