Models from 3ds max lose their transformations when input into XNA

Question

I am making models in 3ds max. However when I export them to .fbx format and then input them into XNA, they lose their scaling. It is most likely something to do with not using the transforms from the model correctly.

Is the following code correct using XNA 3.0?

Matrix[] transforms = new Matrix[playerModel.Bones.Count];
playerModel.CopyAbsoluteBoneTransformsTo(transforms);      

// Draw the model.
foreach (ModelMesh mesh in playerModel.Meshes)
{
    foreach (BasicEffect effect in mesh.Effects)
    {
        effect.World = 
            transforms[mesh.ParentBone.Index] *
            Matrix.CreateScale(Vector3.One*20) *
            Matrix.CreateTranslation(position);

        effect.View = view;
        effect.Projection = projection;                   
    }
    mesh.Draw();
}

It also seems to work if I export it in .obj format, which is probably vertex only format, then import it back into 3ds max and then export it to .fbx for XNA.

Here's an image reference in case you don't understand what I am saying. The left is in XNA and the right in 3ds max.

Answer 1

When exporting, the model data is exported and the transformation data is also exported, they are not baked into each other.

I've seen many folks forget to take into account the transformation data when loading their models into Xna.

If you are properly using a transform array populated by the CopyAbsoluteBoneTransformsTo method then you are using the transformation data (including scale), but not going about it properly would result in a problem you are describing.

If you think this may be a clue, then post your code and we can see if you are coding it properly.

Answer 2

The best solution i found was to reset the xform, In 3ds max

1. In the utilities panel goto "Reset Xform"
2. Then with the model selected click "Reset Selected"

from what i understand reset xform places the mdels transformations in a separate modifier called "xform"

However i still dont understand why xna was unable to just get the transformations from the model