SUMA dimming factor

Hello AFNI gurus,

In SUMA, the default dimming factor for the convexity map can be controlled with SUMA_ConvBrightFactor variable in .sumarc, I think. But it is possible to set the default dimming factor for other data sets, with another environment variable?

In general, how should I think about the dimming factor and its contribution to the colors shown on the surface? I find that setting the dimming factor to 0.5 produces one-to-one correspondence between the colors in the color map and the colors on the surface. Is that the correct interpretation?

Best,

Peter

Hi Peter,

While not positive, I do not believe there is any current
way to initialize dimming factors for general data.

I think the purpose of ‘Dim’ was to just make the colors
less bright, like an alpha control. But the way dimming
was implemented, I believe, the 1-Dim factor essentially
goes to the underlay, all else being equal. The view of
those surface contours can be separately controlled, so
it does not need to be a mix.

  • rick

Hi Rick,

Thanks for getting back to me. I am not sure I understand what you mean. The dimming can be set separately for the curvature and every other Dset the users loads in. The default dimming is set to 0.5 for the curvature, and 0.8 for every other data set. It seems to me that proper correspondence between the color bar/color map and the plotted data can only be achieved with dimming set to 0.5. Since proper correspondence is desirable when generating figures for publication, it would be nice to understand exactly what the dimming does, and confirm that 0.5 is the proper value. It would also be nice to be able to set the default to 0.5 and avoid having to make the change every time.

/Peter

rick reynolds Wrote:

Hi Peter,

While not positive, I do not believe there is any
current
way to initialize dimming factors for general
data.

I think the purpose of ‘Dim’ was to just make the
colors
less bright, like an alpha control. But the way
dimming
was implemented, I believe, the 1-Dim factor
essentially
goes to the underlay, all else being equal. The
view of
those surface contours can be separately
controlled, so
it does not need to be a mix.

  • rick