For this task, I am going to create a new world file, called perfect_world.sdf. It is based on world_01.sdf, so I am only going to show the new model I have added:
As you can see, a new model was added to the world. As its size are 200x200 m and I want it to be centered, I have set the pose's origin to -100 -100.
The model refers to "perfect_topo.dae" file, one we just created. It also refers to scripts and textures directories, something you have already seen in the section where we created a charging station with aruco marker (it used texture, hence the resemblance).
The world file refers to a .material file named perfect.material:
As you can see, all it does is refering to a texture image. Note however, that in original DAE we were free to use texture from any location:
... while in .material file we refer to image in the textures folder. Note also, that image coordinates are normalized to image size, in range of 0-1, so you can use texture image of any size without changing anything in DAE file.