Re: RE: ogc features over orthophoto over dem

Thanks Jim,
the alpha sucks a lot of additional ram, so I switched it off.
Good you asked, since something very strange happens when using alpha:

The photo behaves like having alpha on itself (you can see the
overlays), but it doesn't. You can see the axes, but not the map below.

I also tried to do the alpha with a ConstantMap[], but I went out of
memory with 2 gigs of dedicated ram. And that on a raster of about
200x200. This hurts.

Any idea about the transparency problem?


* [A.D. 14/11/06 09:49], Jim Koutsovasilis <J.Koutsovasilis@xxxxxxxxxx> 
probably wrote:
> Hello Andrea,
> your screenshot is very impressive and inspiring.
> Most of your Display.Alpha code is commented out - I am wondering how
> the screenshot would have looked with transparency turned on.
> Regards,
> Jim.
> ---
> Jim Koutsovasilis
> CSSB / Communications / AMDISS
> Australian Bureau of Meteorology
> Phone: +61 3 9669 4303
> Email: jimk@xxxxxxxxxx 
> -----Original Message-----
> From: owner-visad@xxxxxxxxxxxxxxxx [mailto:owner-visad@xxxxxxxxxxxxxxxx]
> On Behalf Of Andrea Antonello
> Sent: Tuesday, 14 November 2006 05:28
> To: visad@xxxxxxxxxxxxxxxx
> Subject: ogc features over orthophoto over dem
> I prototyped around a little bit adding also shapefiles to my testcase
> and I must say: visad rocks!
> I have huge performance problems, which I hope to resolve somehow later.
> I put the resulting screenshot at:
> I hope someone is interested in this first draft and has some ideas on
> how to do things better. I welcome all critics (Don Murray, I wasn't yet
> able to get things work following your advices, I will come back on that
> later).
> I have a couple of rather different questions I would like to post, in
> the hope they are not too scattered.
> - in visad, is there some kind of caching system that gives the
> possibility to work with huge files that can't be kept in memory? Kind
> of tiling mechanism. LIDAR and friends are a now used reality, has
> anyone experience?
> - in the image I made the river with a Gridded3DSet. I'm not sure if
> that is the proper way. Should I use some VisadLineArray?
> - also, I had to elevate the river of some meter, since in certain parts
> it went below the elevation model (which by the way is right, since the
> river is made of coarser points as the dem and the lines in some parts
> "intersect" the dem). Has anyone a better idea to overlay the shapefile 
> over the dem?
> - I tried to simulate a line with borders by painting a thinner after a
> thicker one of different color. The result is weak as expected, is there
> any way to do styling of lines (apart of dashing, which I read is
> supported)?
> And last but not least (even if really not so important :)): 
> - has anyone an idea about how to put a filled polygon over the dem? I
> tried as a joke to do it with Delauny, but it doesn't permit 3D.
> Perhaps the best would be to create an image and use it as a texture
> over the dem and photo (does this last sentence make a sense?).
> Thanks in advance for any comment.
> Andrea
> =======================================================================
> ======
> To unsubscribe visad, visit:
> =======================================================================
> ======

HydroloGIS - Environmental Safety Modelling
Siemens Str. 19 via Siemens
I-39100 Bozen - Bolzano

Andrea Antonello
Environmental Engineer
tel.     +39 0471 068065  
mobile:  +39 328 8497722
fax:  +39 36 328 8497722
email:   andrea.antonello@xxxxxxxxxxxxxx

"Let it be as much a great honour to take as to give learning,
if you want to be called wise."
Skuggsja' - The King's mirror - 1240 Reykjavik

To unsubscribe visad, visit:

  • 2006 messages navigation, sorted by:
    1. Thread
    2. Subject
    3. Author
    4. Date
    5. ↑ Table Of Contents
  • Search the visad archives: