Wednesday 19 August 2015

Custom Engine...

I've recently been asked which 3D or game engine CAP2 uses so thought I'd post on that topic.

CAP2 uses a custom engine incorporating features such as:

  • 80km draw distance (a prerequisite for a flight simulator)
  • large scale tileable terrain system
  • water rendering system with variable sea states
  • accurate lighting based on world position, date and time
  • accurate star display
  • 3D audio sytem with doppler effect
  • aircraft & watercraft physics systems
  • flexible hierarchical object system

The hierarchical object system allows me to simply add functional components to objects & vehicles so for instance you'll see a wind vane just ahead of the Harrier cockpit showing relative wind motion. This helps during landing, especially with any degree of turbulence.

The physics system allows aircraft to react to a pitching deck through their gear suspension rather than being 'glued' to the deck and ships to have compartments flooded then showing a list or being bow or stern down in the water.

The rendering engine currently uses DX9 though I have an upgrade to DX11 due in the coming months. I'll be adding SSAO (a lighting effect simulating ambient light occlusion) and depth of field effects. SSAO will make the game look a tad prettier while DOF will be used very subtly so that you might not actually be sure it's being used :)

These are all individually simple things which I think add up to a more immersive experience. I do hope you'll agree. Or else!

BTW I read a comment somewhere that stated if a flight sim looked good it must be an arcade sim with 100 missiles per plane, the GPU would be maxed out so the simulation would be rubbish (how?) etc, etc. Well, that's complete bollocks. Pretty much any developer will use or develop an engine where rendering, AI, physics, particles etc exist in separate threads. Rendering should have zero impact on AI depth. Looking good and incorporating a 'non arcade' level sim are not mutually exclusive.
For people wanting a more arcade level experience I've previously posted regarding variable difficulty flight models where landing the Harrier ranges from 'pretty easy' to 'requires attention' to 'a total bitch' :)

Thursday 13 August 2015

To 'VIFF' or not to 'VIFF'...

...that is the question :)

One of the (many) unique capabilities of the Harrier is it's ability to vector it's thrust nozzles during forward flight ( hence VIFF = VectorInForwardFlight ). In a close-in dogfight the Harrier being able to vector more than 23000 lbs of thrust through 98.5 degrees from aft gives an opposing pilot a serious problem most probably resulting in an overshoot and a switch to a defensive posture.

Naturally CAP2 implements this capability. If you fly with a split throttle HOTAS controller or flight stick with two extra analogue inputs you have full control over nozzle position and thrust. Additionally you can map nozzle position increments or absolute positions to other buttons or keys.

Happy VIFFing!

Sunday 9 August 2015

CAP2 Flight Models

There's been a few questions regarding the flight model(s) and simulation level of CAP2 so I thought I'd post regarding flight model difficulty levels.

Basically, I play CAP2 on medium difficulty.

In hard difficulty level, when you attempt a vertical landing on a pitching, crowded deck, managing your throttle, nozzle position whilst monitoring the windvane you get an idea of just how skilled real life Harrier pilots are. It's tough but that's the point isn't it? Playing with TrackIR or a VR headset should help in this mode so I'll post on this once those features are added.

In medium difficulty level your throttle position becomes a climb/descent rate request with engine control logic computing the actual throttle position. It's still demanding but I complete 9 out 10 landings safely.

In easy mode you enter vertical flight mode, set climb/descent rate with your throttle and request longitudinal and lateral movement with your flight stick. Easy.

Why 'SIM155' ?

We intend to write a series of sims and we're located at 1 west, 55 north so we chose 'SIM155'. Actually we're nearer 1w54n but 'SIM154' didn't quite cut it :)


Welcome to my dev blog for everything Sim155 and 'Combat Air Patrol 2' related.

I'll keep you informed about CAP2 development progress, answer any questions and hopefully not swear unless it's entirely justified :)