Jump to content

Some Questions About Cumulusx


Recommended Posts

Hi Folks,

First post, first questions.

Last weekend after doing he FSX Soaring tutorials I tested some free flights and was pretty disappointed on the modelisation lift factors in FSX (thermals, ridge, and wave). So I fell on some tools, downloaded CumulsX and SimProbe and DG808S V3. It's much closer to what it should be now ! So let me first thank all those 3rd Party developpers for their great work.

My questions are mostly about CUmulusX.

1. Is it possible to get rid of the cumulus created over the thermal areas ? I use REX wich has really excellent grafics and ebautiful clouds so the CumulusX cumulusses don't really match this quality and look bad in the sky. I think the FSX soaringbirds animation looks just fine. So what do I need to do if I want to get rid of the cumulus and get the stock fsx natural visualisation soaringbirds back ?

2. FSX Thermal or CUmulusX AutoThermals ? I read that the autothermal feature doesn't take the terrain in account. I mean it does create thermals here and there but not especially over cities or dark fields or where you would expect them in real conditions. Am I right ? What would be the most realistical setting about the thermals: FSX stock thermalls or CumulusX Autothermals ?

3. Can I create a SlopeDataBase with my actual terrain mesh ? I got FSGlobal 2008 which is a really great mesh scenery with highly accurate elevation all around the globe. Now I want to know if I can use this scenery with the SlopeTool to achieve even more realistic Ridgelift than with SimProbe.

That's it for the main part.

Now as I am new I wonder if there are any "must have" Sailplanes (Freeware or Payware). I'm looking mostly for ultra realistic modelled planes with most accurate polarcurves and instrument behavior. The DG808S V3 is the kind of thing I'm talking about.

And by the way is that variometer v2 realistic, I mean is that estimated altitude on WP/GPSP something you find on the real DG808s ? Sorry I'm looking for the hardcore conditions :).

I hope I don't double posted these questions.

Have a great day !

Link to post
Share on other sites

Welcome MNX! I cannot answer any of your questions with certainty, but I know Peter should be here with answers to most of them soon. And I believe Ian may be able to give you a quick answer to the question about the vario maybe.

As far as aircraft go, I can only give you a couple sites that you can search that deal with freeware at least. Wolfgang's aircraft http://www.fsglider.de/index.htm are pretty realistic, but I'm not a real life glider pilot, so I cannot vouch for acuracy (But I trust his aircraft to be as realistic as can be made in Microsoft Flight Simulators). Another person you can try is David Rowberry, I don't know for sure what particular sites hosts all of his aircraft, but start at Simviation http://www.simviation.com/menu.html and maybe AVSIM http://www.avsim.com/ . I have probably downloaded 75-95% (somewhere around 40 or 50 to be somewhat exact) of the freeware gliders available for FSX, and I believe all of them came from those two individuals, with the exception of those found on the SOAR site.

Scott

Link to post
Share on other sites

Hi MNX,

1.) Yes, you can. If you made a backup of the file thermaldescriptions.xml, as recommended in the readme, simply restore it, you get back the initial behavior. Yet, glider pilots like to look out for thermal clouds as indicators for lift. Indeed, thermalling birds are even more welcome, because it is a sure sign (which clouds are not). Unfortunatelly, the FPS hit on FSX is enormous, and still you almost can't see them. In reality they are not that frequent, too. In the next release there will be some improvement here, in particular for low level clouds. The reason for the difficulties here is, that the visuals of the stock clouds use a totally different engine, which is not controllable in detail by addon-designers. So it is not possible to realise a conicidence of lift and clouds. The normal visual engine, that can be used from addons does not support a number of functions, that could make clouds look more natural. Tools like REX and AFX go an replace the cloud bitmap and and realize an own process, that injects weather conditions like cloud layers, winds, etc. into the standard FSX weather engine, which does the rest. They cannot control the appearing of individual clouds at defined locations. BTW, below is a current picture, of my last attempts.

2.) Up to now, Autothermals only consider water, as a nogo for thermals. It is a popular notion, that thermals are preferably developing over dark fields or cities, presumably because of MS writes this in the manual. Correctly, thermals are developing anywhere, though there are some preferences. If you have a high altiude you could hardly find the ground trigger location anymore. In open country, thermals triggers include also towers, edges of forests, small ridges, in short discontinuities of the landscape. CumulusX! does recognize the influence of mountain slopes regarding to wind and sun irradiation, if a valid slope data base exists for the current area.

In reality, glider pilots have to avoid large cities anyway for safety reasons, and moreover, thermals there are frequently very uneven, and short term. Soil humidity is important also.

Unfortunately, it is not possible for me yet, to probe ground properties in detail in real time since FSX offers only a set of 24 ground types, for the purpose of determining the touch down conditions. Yet there is a little bit more room for it, since ice, snow, and forests can be detected. Hope the best of a next release.

3.) No. It is not possible (for me) to extract elevation data from the mesh bgls. What you could do instead, follow the links in the docs of the SlopeDataBase tool, to download digital elevation data, preferably from the CIAGR organisation, its free for private purpose. This is stemming from the SRTM radar mission, and most probably has a 99.9 overlap with all free and commercial mesh bgls. Instead you can use Sim_Probe of Ian Lews, which extracts the slope situation of the nearest neighborhood in realtime during flight. This will fit to any effective terrain mesh. It does not support, however, the placement of thermals in mountains.

To your last question: Gliding computers are almost a standard in modern gliders, you may search the web for GPS_LOG, or Henryk Byrecki, which shows a nice example for PDA-based solution. But be warned, the doc is heavy stuff.

best regards,

Peter

post-24548-1238757783_thumb.jpg

Link to post
Share on other sites

Allright, thank you for your quick answers. I'm gonna set up my FSX this week-end and test out for the best settings to me :). Gonna test what workds best between Sim Probe and the Slope Data Base too. (Maybe some FPS differences ?) I'll check this out and post back my final settings.

Have a great day !

Link to post
Share on other sites

MNX for ridgelift:

CumulusX can calculate ridgelift using an approx 90x60m grid anywhere in the world you can download an elevation model with at least that resolution, but it needs a pre-compile step and has a relatively simplistic calculation looking at the local patch immediately beneath the user aircraft.

Sim_probe reads the terrain mesh within FSX which has a 78m grid for Europe and North America but less elsewhere. Sim_probe looks at the slope beneath the user aircraft but also looks at the profile a fair distance upwind (and a little downwind) to see if the local lift should be modified e.g. due to higher ground upwind.

The cpu impact of ridgelift calculation in both sim_probe and CumulusX is totally insignificant.

An installed add-on terrain mesh is automatically used by sim_probe but for North America and Europe the pilot wouldn't be able to spot a difference in the ridgelift calculated because the default is already accurate enough that other variables (e.g. turbulence, gusts) will swamp the diminishing detail improvement in lift calculation.

Ridge soaring missions (e.g. see www.flightsimulatorxmissions.com) assume the use of sim_probe if you want to compare your time with other pilots.

Peter feel free to negate this view but I would suggest CumulusX for thermals + sim_probe for ridge lift is the default assumption for FSX soaring pilots unless there is a particular interest in a more detailed DEM file for an area of South America or Asia.

B21

Link to post
Share on other sites

Some more Qs:

I downloaded some files ine arcascii *.asc format. As I got fairly many of them I would like to convert them all at once (I don't want to do the file/import step for each one...) is there any way to launch a massive import of arcascii files ?

What calculation do you think is best/more accurate for ridge lift (not talking about mountain thermals) between the sim probe which reads a little ahead of the plane too and the slope data base tool which uses tiles around the flight zone ?

I'm thinking a bit before trying to convert such a big amount of data..

Have a great day !

Link to post
Share on other sites

MNX,

have you identified some area in FS Global 2008's terrain coverage that is less accurate than these DEM files and are expecting to fly there? Antarctica maybe ?

B21

Link to post
Share on other sites

Haha, I'm just looking for those mountain thermals, and sometimes the updraft seems to behave strange according to the terrain. Nevermind I'm splitting hairs that's true :).

And no, FSGlobal is better allround the globe compared to the SRTMv4 still a 90 mesh.

Good night there !

Link to post
Share on other sites

Hi MNX - if you fancy trying mountain soaring here's a quick 'getting started' guide:

1) Try the 'Austrian Soaring Day 4' mission available here. This uses standard FSX mission objects for thermals and ridgelift and doesn't need CumulusX or sim_probe, but it doesn't really matter if you have those installed. This mission is a pleasant flight around the Alps.

2) Install CumulusX! and sim_probe

3) For mountain soaring using CumulusX and sim_probe, try the 'Dornbirn Day 1 to 3' missions by SPUD, see links on the flightsimulatorxmissions.com New Missions forum

4) For missions predominantly using ridges, but sometimes needing thermal climbs for upwind jumps, try the Mifflin Soaring Competition which is set of five missions representing a regional soaring competition on the Appalacian ridges in Pennsylvania. Also via the same link is a mission for the actual task and weather for the first day of the USA 2008 18m Nationals, which definitely requires ridge running (sim_probe) and thermalling (CumulusX) skills.

5) Pilot attempts at these missions are recorded on the flightsimulatorxmissions.com forum linked in (3) above so you can see how much you get whupped by people like Hodge and lowlevel. e.g see this forum post. Or feel free to post here.

6) sim_probe is automatically recording a flight log (aka 'IGC file') of every flight you take. These can be posted to everytrail.com if you want to share your mistakes... the general routine is only look at someone elses flight log *after* you've completed the mission but it doesn't really matter. E.g. see this log for the 2008 USA Nationals Day 1 from Hodge. These logs are generally a hell of a lot more interesting once you've struggled around the course.

B21

Link to post
Share on other sites

Hi MNX,

basically, the slope-data base and sim_probe are pretty comparable in effect. The main difference is, that with a slope data base, the placement of thermals in mountain areas considers the sun irradiation and wind influence.

This happens, if a valid slope data base exists for the current area. Still you can use sim_probe in parallel to calculate the ridge lift. If want to deactivate the mountain effects, make an empty entry for the slope data base directory.

Batch import is currently not possible (unless you make your own windows automation).

best regards,

Peter

Link to post
Share on other sites
Hi MNX,

basically, the slope-data base and sim_probe are pretty comparable in effect. The main difference is, that with a slope data base, the placement of thermals in mountain areas considers the sun irradiation and wind influence.

This happens, if a valid slope data base exists for the current area. Still you can use sim_probe in parallel to calculate the ridge lift. If want to deactivate the mountain effects, make an empty entry for the slope data base directory.

Batch import is currently not possible (unless you make your own windows automation).

best regards,

Peter

Is there anyone in Houston that can help me set up CumulusX! and simProbe on my computer? I have tried, and failed a couple of times.

binky9@ix.netcom.com

Link to post
Share on other sites
Guest
This topic is now closed to further replies.
×
×
  • Create New...