• Licensed version of ClearView RC Flight Simulator
• Licensed version of ac3d
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• Example Models

 

ClearView uses quite advanced physics simulation to provide very realistic interaction between the model and the world objects.  The model as represented in model.ac is built with many thousands of surfaces and is optimised for best visual representation (rendering). While the same model can be used for collision detection and ground and world objects interaction, this is not practical from performance standpoint. For that only reason, ClearView uses a separate 3d model, as created in colbody.ac for the colision detection and object interaction. This model is a simplified version of the model in body.ac.  The plane I am working on is created with very few surfaces and is quite optimal (the surface count is low). If I look in ac3d, in Tools, then Model Info I can see that the model has 25 objects, 1999 surfaces and 1806 vertices. Because of that , I save body.ac as colbody.ac and I will be able to load the model in ClearView and the program will work fine on faster systems. Further optimisation is needed to create efficient model for slow computers. Let's load 03FirstPlane001 in ClearView and try it. If the model is slow, continue with the next step. You can see now that the model will crahs and reload if you hit the ground with the propeller. This is because the propeller disk is named propdisk - when ClearView detects that object named propdisk hits the ground or another object, ClearView will stop the engine and mark the model as crashed. The program will then waith a number of seconds as defined in crashResetTime parameter in startupParams.txt and will then reload. Another special object names are maingear1, maingear2, tailgear and nosegear. ClearView provides special handling for such objects and they behave as model wheels. ClearView turns tailgear and nosegear accordingly so the model can taxi on the ground properly. To ensure consistent ground handling, it is required that each of these gear objects ends with a simple triangle that points down - so it touches the flat ground surface at exactly one point. Here is how colbody.ac looks in step 1 (colbody.ac is simply taken from body.ac):

 

 

 I will examine every part for complexity. If the part is made from too many surfaces, I will replace the part with simplified part that will be used for collision detection. The simplified part approximates the original part but is much simpler.  That improves the program performance on slow computers. This model wings are very low complexity. Normally, I will not simplify them. However, here is an example how a wing can be made simpler:

The simpler wing will replace the real wing in colbody.ac In collision, it will behave the same, but ClearView will run faster.

Let's look at model 03FirstPlane003 - I have optimized colbody.ac by replacing every object with similar form and size object with simplified geometry. The old file had 1999 surfaces and 1806 vertices. The new file stats are shown here:

Not bad. The new file has 169 surfaces vs 1999 for the old one and 279 vertices vs 1806 in the old one. This model will perform well on much slower computer and the behavior of the parts will be the same. Please note that normal model has about 5000-9000 surfaces and if not optimised, colbody.ac may lock even the fastest computer, because the computational requirements for collision detection increase in exponential manner.

 

Making breakable parts is easy if the model is properly created so each model part that can break is created as separate object in ac3d. Once proper bode.ac and colbody.ac files are created, we create breakable parts by simply adding a command "breakpart" in params section for each part we want to define as breakable.

Here is the checklist we must verify before adding breakable parts command in params.txt:

 

 

If you go over the checklist and feel you have all in order, you are ready to add breakable parts in params section of params.txt

 

Here is the format for the breakpart declaration:

 

 

All speeds in breakpart declaration are in meters per second (m/s). One m/s is 3.6 km/h or 2.2 MPH (miles per hour).

 

partName - the part name. Must be the same in body.ac and colbody.ac

partType - 1 for all simple parts, 10 for prop disks, 12 for helicopter tail disks, 20 for helcopter rotor disks

horisontalSpeed - the part will break off if the part hits an object with horisontal speed component greater than that

verticalSpeed - the part will break off if the part hits an object with vertical speed component greater than that

crashSpeed - the part will break off if the model crashes awith speed greater than that

breakForce - (in Newtons) the part breaks if the part is hit with a force higher than that 1 kg object applies 9.8 N force on the ground)

partMass -part mass in Kg - leave it as 1 for now

partId - part id number (unique for each part)

childPartId1 - child part id. If the part breaks, the child part will break as well

childPartId2 - second child part id. If the part breaks, the child part will break as well.

 

 

Let's load model 03FirstPlane003 and open the Advanced Settings - we will see how I defined the breakable parts for this model:

 

 

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