So I've got a grid of cubes and I'd like to allow the player to swap positions with the cubes that are adjacent to it. Right now I have a 2d array of world matrices available to my game board class and I'm using Matrix.Lerp to animate between the two positions. However, when I originally created these matrices, I used Matrix.CreateTranslation to a vector scaled by the size of my cubes. However, I don't apply this when I swap positions, so the new positions of the cubes don't line up with the grid anymore because their movement hasn't been scaled. Is there any way to do this if I"m calculating the matrices this way? Code below:

Since all of the blocks use the same offsets and scale, I think the easiest way to accomplish this would be to change how you're transitioning blocks. I would add an "in-between" state so you don't have to change the actual destination world transforms:

Then initialize Destination and PrevLocatation to what you're initializing the World matrix to in the code you posted, and use CurrentWorld instead of World everywhere else.

This worked, but it needed one minor fix. Between setting the previous locations to CurrentWorld and setting the destinations, the return value of CurrentWorld changes. In fact, it flipped the sign of one of the matrix entries as it prepared to transform in the opposite direction (I presume.). So I just stored CurrentWorld for both blocks before setting it so the linear interpolation wouldn't start between those calls and cause one block not to move.