[IDV #MQO-669339]: IDV v2.5: Transparency of thickness vs. temperature color-filled plots

Hi Dave-

> I just created a display (IDV 2.5, Mac OS X 10.5.4, MacBook Pro) that
> includes the following:
> 
> (1) 500 mb geostrophic wind vectors
> (2) 850 mb geostrophic wind vectors
> (3) 700 mb temperature (color-filled contours and line contours)
> (4) 850-500 mb thickness (color-filled contours and line contours)
> 
> (Of course, I don't try to show (3) and (4) at the same time.
> 
> I've made the two color-filled contour plots 70% transparent. As a
> result, when displaying the 700 mb temperature plot, it's possible to
> see the 850 mb geostrophic wind vectors through it, as well as the 500
> mb geostrophic wind vectors on top of it. This is what I want.
> 
> However, I also want to be able to adjust the vertical position of the
> thickness contour plot so that it is located between the 500 and 850
> mb geostrophic wind vector plots, and be able to see through it to the
> 850 mb geostrophic wind vectors, just as I can do with the 700 mb
> temperature plot. Unfortunately, when I do this, even though the
> thickness contour plot has got the same transparency as the
> temperature plot, it completely obscures the fields below it
> (including the map background).
> 
> How come?

Transparency is order dependent.  Whatever you want to be transparent
should be added last, (so previous things show through it).  

> I've attached bundle to illustrate the issue. In it's current state,
> the bundle has the vertical position of the thickness contour plot at
> the bottom of the sliding scale, so you'll have to move the slider
> between "bottom" and "middle" to see the problem.

In this case, the vectors were added after the color filled contours
so they are "in front" of the transparency.  So as you move the color
filled slice above them in the viewing plane, they are hidden. 

Anything you want transparent should be added last, or use the display
control's View->To Front menu to bring them to the front.  This removes
the display and re-adds it "last".

Don
> 
> -- Dave
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 


Ticket Details
===================
Ticket ID: MQO-669339
Department: Support IDV
Priority: Normal
Status: Open