Actually to test the exported model itself you could just take my sample, and substitute your FBX model into it to see the spheres.

• Add it to the Content\Meshes
• Add a texture file with a matching name in Content\Textures.
• Add a really simple XML file with matching name into the MeshInfo folder. something with just one BoundingPart with xyz’s=0.5, 0.5, 0.5 and w=1.0
• Change the line of code that defines which model it loads. private string _modelContentName = "TutorialPlane";

… and voila, you should see what XNA’s derived sphere looks like.

cheers for input

So with Debug rendering of the spheres you could check the sphere represents the extent of your model’s geometry, and is not wildly different.

The modeling tool/export you use may be exporting Camera/lighting objects etc… as part of the FBX and confusing things perhaps?

would be great to have such a chance, though if thats your own plane not only hats off; as i think its cool, but can understand why you don’t want mine

again take care my man

Hmmmm…. puzzling.

Best bet is being able to visualize what these BoundingSpheres look like.
If you look at my sample I have a code for rendering the spheres.
See you if you can hack that into your code. It might give you a clue as to what’s going wrong. Like, are they too big? in the wrong place? etc…

Debug rendering stuff is great when you’ve got it working. But while I was debugging that I was not always sure if it was my debug rendering code at fault, or truly the Spheres. I got it working in the end, so perhaps you could try that too.

take care

This is the first time I’ve actually looked at the “60 mins” tutorial, but here’s a thought to consider…

Do you scale you models when you draw them at all?

In the their tutorial they don’t appear to be scaling their model when it draws. So their mesh’s BoundingSphere.Radius will be correct.
However, if you are scaling your models, you need to make sure you factor that into the BoundingSphere size as well.

So, if you Draw your models at 3 times the size, remember to triple the mesh’s BoundingSphere.Radius as well.
Likewise if you are making things smaller.

currently working on a version of the classic ‘asteroids’ though in mine you shoot at russian sats lol. Anyhow my boundingsphere code is pinched from the tutorial ‘Make a game in 60 mins’ > http://msdn.microsoft.com/en-us/library/bb975644.aspx <

i am having trouble as they seem to happen at random rather than as expected can you possibly give me some pointers (well more pointers) as to make these collisions more reliable

would be much appreciated