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Project Apollo - NASSP 6.4.3 released!
25068 Posts in 2094 Topics by 2266 Members
Latest Member: twa517
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31  Project Apollo - NASSP / Planning / Landing the LM on meshes on: January 20, 2006, 02:13:15 PM
Tschachim: No problems, noone is mistake-proof.Happy

LazyD: If the "huge negative altitude" is -1e100 or ~ -2147483648 then i guess the answer is "case-sensitive".
The PCHAR PlanetName is case-sensitive, so i recommend using the oapiGetObjectName(vessel->GetSurfaceRef(),pname,5); - style call.
32  Project Apollo - NASSP / Planning / Landing the LM on meshes on: January 20, 2006, 01:52:39 AM
Well, iam impressed.
Never thought an EVA will run so smoothly on the mountains - normally there was a lot of bugs...
Good job so far!

"rebundled" Meshland package is not a problem.

A small point - Apollo 14 - LM final approach scenario put you in LEO with uninitialised auopilot, while auto-behavior explained in the link is more likely to be Apollo 14 - LM before powered descent.scn.

About the interface:
Ive downloaded the CVS sources, and there is a strange mix of versions there - Meshland test packages comes with Visosad engine 1 (Meshland 1.1), but the modules uses engine 0 interface.
For version 1.1 the
#define VS_CTT_FAST 0
#define VS_CTT_INBLOCK 1
constants is obsolete, as well as "int type" parameter in *ElvLoc function.
33  Project Apollo - NASSP / Planning / Landing the LM on meshes on: January 14, 2006, 05:07:53 PM
Yes, the one set by SetSize. It is used for volumetric collisions, while touchdown points determines the tilt and LANDED status.

The size is read at every step, so there should be no issues.
34  Project Apollo - NASSP / Planning / Landing the LM on meshes on: January 14, 2006, 04:35:29 PM
Greetings again.

There is a severe update for MeshLand, look at the main forum. (Just in case).
Ive reworked the performance issue - now there is no speed diffirence between the maximum altitude function and the main collision check loop.

So, how's it going? Any problems?

Is this the CVS mentioned: co -P projectApolloSource ?
35  Project Apollo - NASSP / Modeling / Taurus-Littrow Valley Project at full throttle again... on: January 14, 2006, 04:29:27 PM
That looks very promising. If that's just an early beta, then the release one will definitely rock! Keep it going.

One small comment - Even the new Visosad engine cannot process an array of small boulders with 1000 polys per unit without a performance loss (that's what rocks in current NEP looks like), so it's a good idea to keep them simplier.
36  Project Apollo - NASSP / Planning / Landing the LM on meshes on: December 28, 2005, 04:49:43 AM

I was a bit busy last time. Consequently the update was buggy and not too useful. Update to it below.

There is no need to make a special ProjectAppolo Meshland version, since there is nothing special to include in it except the compatibility problems.

About MeshLand in general: The collision engine works properly in altitude range of 0 to ~200*vessel_cog_elevation.
Going higher can produce landing bugs.
It allows going below the sphere of the planet but you cannot land there, since Orbiter don't support negative landed altitude.
The collision engine is volumetric. Means you make caves and canyons, can collide with the wall or cave top. But this sort of collisions is not recomended, since they're bugs, not features.
Mesh size is not calculated, collisions is checked for sphere of vessel's mean radius. There is an option to use touchdown points to determine tilt, but it's 4 times slower and compiled out.
It's highly reccomended not to use an rocks array with 1000 polys-per-rock, since it slows the thing down.

It is a fact that all Visosad bugs can be fixed by adding ~3 lines to Orbiter code. The problem is to convince our great Dr. Martins to do it.

Here is another update:

It includes:
double VSGetElvLoc (OBJHANDLE VesselHandle,double lat,double lon,double alt,int type);
Returns elevation with vessel reference.

double VSGetAbsElvLoc(PCHAR PlanetName,double lat,double lon,double alt,int type) ;
Returns elevation with explict point reference.

VS_CTT_FAST - Returns volumatric reading, fast.
VS_CTT_INBLOCK - Return the maximum elevation within base block, slow.
VS_CTT_ABSOLUTE - Return the asolute maximum elevation without  limit cheks, very slow.
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