Hi Don,
On 2007-05-24, at 12:35 , Don Murray wrote:
Hi Ken-
Ken Mankoff wrote:
I've browsed the manual and think the answer to the following
question is
'no' (at least I didn't see any screenshots that showed this) but
want to
check here.
Can IDV do transparent iso volumes rather than hard iso surfaces.
Sample
screenshot of what I'd like to do in IDV is here:
http://edgcm.columbia.edu/~mankoff/fuzzy_volume.png
I know IDV can do the gray iso surface, but what about the yellow/
blue?
You could do this with a combination of the Volume Rendering
control and an isosurface. Set the transparency on the volume
rendering to be about 90%. You'll also need to use the View->To Front
option for the Volume control to be able to see the embedded
isosurface.
OK I forget about Volume Rendering (FYI that string isn't even in the
manual). I've done that. By default, I cannot see through the top
layer, so I set the transparency of the colorbar. Example screenshot
is here:
http://edgcm.columbia.edu/~mankoff/IDV.png
But there is a difference between this and the previous image. In the
original image, transparency is a function of data value (in addition
to color). What I've done in IDV has color as a function of value,
but transparency is just applied to the whole data set uniformly.
I chose 50% transparency in the above image. For this specific image
it looks like since there are 4 layers that each layer is 12.5%
opaque (87.5% transparent). The four layers therefore are 50%
transparent as a total.
Is there a different way to get transparency applied to the data set
as a function of the data set? For example, looking at a rain cloud,
I'd like to color the data based on moisture content, but have
transparency based on particle density. This would give a somewhat
realistic view, in that when there are more particles it gets harder
to see through a cloud.
Also, on this image, I've added an isosurface, but I cannot see it
through the 'transparent' volume layers.
http://edgcm.columbia.edu/~mankoff/IDV.png
-k.
