Question

I have created a XNA game background as a model, but it contains more models inside. For example: “ground contains a ball”. Now, what I want to do is go inside the Ground and retrieve the ball and resize it.

Is there a possibility of doing this or do I need to import ground and ball separately and then resize it (I would prefer this to be the last option)?

Answer 1

I think what you mean is that you want to scale a specific ModelMesh inside a model. This can be done using a Matrix array, which will contain transforms specific to individual meshes. Something like this:

//In the class for the background, or the game class if there isn't one
Matrix[] specificTransforms;

//Initialize the array however you want, and assign the specific matrix for the ball to its corresponding index

//Loop through the meshes like usual but add this below your code that multiplies the transform matrices:
if (specificTransforms[(put your iterator variable here)] != null)
{
    (put your BasicEffect here).World *= specificTransforms[put your iterator variable here];
}

This will combine the world matrix for the mesh with the specific transformation that you want to apply to the ball.

This is not the best way of doing it, and it would be easier to give you an example if you post the code that you’re using. Unless you do that, there is no guarantee that this will work.