# Makie don't use full color range in volume plots. (What am I doing wrong ?)

**URL:** <https://discourse.julialang.org/t/makie-dont-use-full-color-range-in-volume-plots-what-am-i-doing-wrong/103785>\
**Category:** Visualization\
**Tags:** question, plotting\
**Created:** [September 12, 2023, 12:04pm UTC](https://discourse.julialang.org/t/makie-dont-use-full-color-range-in-volume-plots-what-am-i-doing-wrong/103785 "2023-09-12T12:04:12Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![Knud\_Sorensen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/knud_sorensen/32/52401_2.png) [@Knud\_Sorensen](https://discourse.julialang.org/u/Knud_Sorensen)\
**Post date:** [September 12, 2023, 12:04pm UTC](https://discourse.julialang.org/t/makie-dont-use-full-color-range-in-volume-plots-what-am-i-doing-wrong/103785/1 "2023-09-12T12:04:12Z")

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Hi. I plot at 3D array using:

```julia
f=volume(vol; colormap=:redsblues, colorrange=(-2.0,2.0), lowclip=:red, highclip=:blue)

```

But the plot doesn’t contain red. What is worng ?

 ![qlense2-2023-09-12T12:07:36.739](https://global.discourse-cdn.com/julialang/original/3X/2/b/2bd622663ce345b9e0e0e5b7e34355839838299d.png)

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**Author:** ![sdanisch](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/sdanisch/32/1406_2.png) [@sdanisch](https://discourse.julialang.org/u/sdanisch)\
**Post date:** [September 12, 2023, 12:07pm UTC](https://discourse.julialang.org/t/makie-dont-use-full-color-range-in-volume-plots-what-am-i-doing-wrong/103785/2 "2023-09-12T12:07:36Z")

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Ugh, we still haven’t implemented that and since we dont error right now, this just doesn’t use lowclip/highclip.  
Guess you have to do this for now:

```julia
cmap = to_colormap(:redsblues)
cmap[1] = to_color(:red)
cmap[end] = to_color(:blue)
f=volume(vol; colormap=cmap, colorrange=(-2.0,2.0))

```

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<div class="post-metadata">

**Author:** ![Knud\_Sorensen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/knud_sorensen/32/52401_2.png) [@Knud\_Sorensen](https://discourse.julialang.org/u/Knud_Sorensen)\
**Post date:** [September 12, 2023, 12:31pm UTC](https://discourse.julialang.org/t/makie-dont-use-full-color-range-in-volume-plots-what-am-i-doing-wrong/103785/3 "2023-09-12T12:31:26Z")

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I still don’t get any red.

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<div class="post-metadata">

**Author:** ![Knud\_Sorensen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/knud_sorensen/32/52401_2.png) [@Knud\_Sorensen](https://discourse.julialang.org/u/Knud_Sorensen)\
**Post date:** [September 12, 2023, 1:47pm UTC](https://discourse.julialang.org/t/makie-dont-use-full-color-range-in-volume-plots-what-am-i-doing-wrong/103785/4 "2023-09-12T13:47:46Z")

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It just looks like it completely ignores negative values.

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<div class="post-metadata">

**Author:** ![sdanisch](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/sdanisch/32/1406_2.png) [@sdanisch](https://discourse.julialang.org/u/sdanisch)\
**Post date:** [September 12, 2023, 2:09pm UTC](https://discourse.julialang.org/t/makie-dont-use-full-color-range-in-volume-plots-what-am-i-doing-wrong/103785/5 "2023-09-12T14:09:30Z")

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Can you open an issue with an MWE?

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<div class="post-metadata">

**Author:** ![Knud\_Sorensen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/knud_sorensen/32/52401_2.png) [@Knud\_Sorensen](https://discourse.julialang.org/u/Knud_Sorensen)\
**Post date:** [September 12, 2023, 2:25pm UTC](https://discourse.julialang.org/t/makie-dont-use-full-color-range-in-volume-plots-what-am-i-doing-wrong/103785/6 "2023-09-12T14:25:33Z")

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Sure, for now. I did.

```julia
min, max = extrema(vol)
nvol=vol.-min
volume(nvol; colorrange=(0.1,1.2), colormap=cmap)

```

The red color is back, but its absorption is low.  
What I think is happening is that the absorption is scaled with the value of the data and when the value is negative it becomes negative or zero, and you can see the red color. Scaling absorption with the abs() of the data would be better.

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<div class="post-metadata">

**Author:** ![Knud\_Sorensen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/knud_sorensen/32/52401_2.png) [@Knud\_Sorensen](https://discourse.julialang.org/u/Knud_Sorensen)\
**Post date:** [September 12, 2023, 4:06pm UTC](https://discourse.julialang.org/t/makie-dont-use-full-color-range-in-volume-plots-what-am-i-doing-wrong/103785/7 "2023-09-12T16:06:20Z")

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I am working on an example that shows the problem. But the best way to see the problem with intensity, is if you view it from an eye position that goes along with z=0. What is the easiest way to move the eye position ??

```julia
using GLMakie

xs, ys, zs = [-10:0.1:10 for d in range(1,3)]

vol = [z/sqrt(x^2+y^2+z^2+0.0001) for x in xs, y in xs, z in zs]

min,max=extrema(vol)

f=volume(xs,ys,zs,vol; colormap=:redsblues, colorrange=(min,max))

save("volmwe1.png",f)

vol=vol.-min

g=volume(xs,ys,zs,vol; colormap=:redsblues, colorrange=(0,max-min))

save("volmwe2.png",g)

```

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<div class="post-metadata">

**Author:** ![Knud\_Sorensen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/knud_sorensen/32/52401_2.png) [@Knud\_Sorensen](https://discourse.julialang.org/u/Knud_Sorensen)\
**Post date:** [September 18, 2023, 12:50pm UTC](https://discourse.julialang.org/t/makie-dont-use-full-color-range-in-volume-plots-what-am-i-doing-wrong/103785/8 "2023-09-18T12:50:23Z")

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Adding `algorithm=:absorption` solves the problem.