OHM J-3 Cub Lua Script Vessel Add-on for OpenOrbiter 4

[misha.physics]

Thanks. I've just tried it with the last OpenOrbiter and it works.

Sorry, could I ask you what is the "Lua Script Vessel" and where you take the syntax? Are you just writing the code in any text editor and set the extension to *.lua?

A lot of the Lua capabilities are documented under the Help button on the Orbiter splash page. For the rest, you probably will want to look through the Lua Scripting pages on this forum.

What the splash page and Help button did you mean there?

 

[Thunder Chicken]

Thanks. I've just tried it with the last OpenOrbiter and it works.

Excellent!

Sorry, could I ask you what is the "Lua Script Vessel" and where you take the syntax? Are you just writing the code in any text editor and set the extension to *.lua?

This is correct. It's just a text file with a *.lua extension. You can see the scripts for the J-3 under Config/Vessels/J-3. No C++ modules needed to be compiled. Orbiter has an interpreter that can read the Lua scripts and interpret them with existing methods. Works well.

What the splash page and Help button did you mean there?

When you start Orbiter, on the bottom right of the dialog is a Help button. A lot of basic Orbiter script methods are listed there, but a lot of methods were only added to Orbiter in the last several weeks, so the documentation is incomplete. They are similar to those in the C++ API.

 

[misha.physics]

on the bottom right of the dialog is a Help button

Do you mean this?:



This help pages are just only available in Orbiter 2016, not OpenOrbiter yet, but if I understand correctly the base syntax is working, isn't it?

 

[Thunder Chicken]

Do you mean this?:

View attachment 38991

This help pages are just only available in Orbiter 2016, not OpenOrbiter yet, but if I understand correctly the base syntax is working, isn't it?

Yes, that's correct. There are a lot of Lua Script methods documented there, but there are a lot of critical methods that were only developed in the last few months which aren't documented there. Until the documentation catches up, I have found the least bad thing to do is look at the C++ API_Reference.pdf in the Orbiter 2016 documents, and see if you can find Lua equivalent methods in the Help pages or by searching the OpenOrbiter code base. There are complete DG and Atlantis versions ported into Lua script that are useful to examine. Being able to make more-or-less complete vessel add-ons with Lua script is a very new capability, and certain things are still being refined.

 

[Thunder Chicken]

Thunder Chicken updated J-3 Cub Lua Script Vessel Add-on for OpenOrbiter with a new update entry:

Improved Airfoil Properties and CG

Improvements in this version:

1. Updated with mesh shifted to put CG in center of literature range for J-3
2. Improved lift and moment coefficients for USA 35B airfoil from NACA TN 219

These changes generally reduce the magnitude of elevator trim changes to maintain level flight as airspeed changes and eliminates falling-leaf hunting of angle of attack.

Considering updating the propeller mesh to improve its look and reduce poly count. Also considering 3D bouncy tires for...

Read the rest of this update entry...

 

[Thunder Chicken]

Thunder Chicken updated J-3 Cub Lua Script Vessel Add-on for OpenOrbiter with a new update entry:

Reciprocating Engine and Propeller

Some major improvements to this add-on.

• Implemented Otto cycle model for reciprocating engine performance. Matches power and fuel consumption of an A-65 engine very well. Inputs are engine displacement volume (in cubic meters) and compression ratio.
• Implemented a momentum disk model of the propeller which translates the calculated engine power to thrust. A root finding routine solves for the air velocity exiting the propeller at a given power, which provides the thrust applied...

Read the rest of this update entry...