hi, this may cosmetically feature but can be usable for direct comparison. Jet type colormaps is default result plots in Code_Aster and Dlubal RFEM, it has darked level to impress comparing to default rainbow type in PrePoMax. Also, jet type is rainbow in CalculiX GraphiX (CGX) and will be complete enough if available, thank you.
image from OpenGeosys
indeed, it’s a colormap preset named Jet in ParaView widely used by many FE also.
Personally, I have never understood the standard color maps. I know that nowadays the standard cannot be changed, but to me it doesn’t make much sense.
The human eye is more sensitive to greens. (Perhaps evolution favored this to distinguish the subtle variations of green in different plants and more easily recognize edible ones).
In finite element analysis, the color we intuitively pay the most attention to is the most irrelevant.
I understand that this is very personal and that each person perceives colors differently, but for me, having green in the center of the color range is annoying. That’s why my palette tries to avoid it, apart from the fact that I selected the extremes at the time inspired by a painting that I really like.
Here’s a nice study about colormaps: How to Choose Abaqus Colormaps
There are also research papers on this topic such as: A Survey of Colormaps in Visualization - PMC
But having more types of colormaps or being able to customize them like in Abaqus should be enough for us.
my personal opinion for bright at center mostly not good since it represents neutral ranges. This can be easily checked by plot in lowest and highest results value, more problematic or have no sense with the same sign of value in ranges. Some is usefull for brittle like material to separated tension and compresssion, so there’s red-blue and white at center. However, cool-warm is a bit different since using grey color not white and capable to fit in general conditions.
if more colormap preset need to be added, i will’ suggest another one like ‘Rainbow Blended Grey’ similar to classic FE used by Femap, SAP2000 or CGX
Since colormaps are used everywhere in science, there are many studies about them. I really don’t want to go deeper than necessary into it, but the issue of bright transitions is discussed e.g. here: https://colorcet.com/
There’s also a quite long explanation of why Matplotlib chose Viridis instead of Jet for their default colormap: https://www.youtube.com/watch?v=xAoljeRJ3lU
science can have large branch, but finite elements specific in results i.e displacement, stress and strain. Many FE software locked this feature, this means colormaps only have single preset it cannot be changed and they chose rainbow family since bright have two inside the ranges (cyan and yellow). Two bright colors in ranges made it clearly in separation value, not to meaning neutral as in single at center. Viridis maybe good due to its linearity from low to highest level of spectrum but not clear in separation value in ranges, become rare in use of FE results except thermal analysis probably. It seems not any FE software used it as default, mostly rainbow family and they chose jet type for single preset.
this is not about what’s good colormaps to choose as i stated in the beginning, only cosmetically feature for completeness and direct comparation to others. However, later one talk to restrict the scopes of proposed feature by showing best colormaps and bad at another.
your presentation link of video is recommended to use coolwarm as coloromap preset and no relation to viridis, this type is available since early version of PrePoMax and being used as default in single preset. I also added this type in CalculiX GraphiX (CGX) with permission to the author by contacting directly.
I have added the Jet colour map.
The first line is from the OP image, the second from ACTIVIZ, and the third line is from PrePoMax when Brightness is set to 0.
Even within FEA, it also depends on the application. For example, it makes more sense to display fatigue life results using a reversed rainbow map. Heat transfer is sometimes better visualized using thermal imaging-like or black body radiation colors.
There are some common aspects with other areas of science too. Such as the issue of fake hotspots due to high contrast as discussed on the website I linked above.
thanks much.
indeed, i’m also notify about specific colormaps usefulness for thermal analysis and brittle like materials.
