How does a bulldozer deform terrain?
Terrain deformation for this project is not enough. We have to deform it the way a bulldozer would change terrain in the real world. A bulldozer actually does this in very specific ways. There are two major categories of terrain deformation that we will be dealing with.
First is positional deformation. This means that we will deform the terrain based on the position of the bulldozer and its blade. This may seem obvious, but we need to take into account a number of factors.
If we know that the bulldozer is below the level of our virtual terrain then we need to deform the terrain to match that level.
* terrain lowered to meet bulldozer, shown in blue
If we know that the bulldozer is above the level of our terrain then we need to raise the level of the terrain to bring it to the bottom of the bulldozer.
* terrain moved up to meet bulldozer, shown in blue
If the bulldozer moves along and encounters some dirt, we need to push that dirt in front of the bulldozer. If we are pushing dirt and go over a portion of the terrain that is lower than our bulldozer, then we need to fill that portion with the dirt.
* blade moves across the terrain and levels it as it goes along, removed material shown in red, deposited material shown in blue
The second type of deformation is what we call approximate or predictive deformation. Because the bulldozer can’t give us exact information on how much dirt it is pushing or carrying, we are approximating the amount of material that is being moved based on information like the volume the blade can hold.
This particular bulldozer can lift and carry material so we need to approximate how much it can carry and then raise the terrain when it drops the material from the bucket.
*dropped material shown in blue
As the bulldozer moves along the terrain and has the maximum capacity of material in the blade, it will leave a falloff or wake of dirt to sides of the bulldozer. We will approximate that information as well.
