Squeezing shape by another one I'm trying to simulate the growth of a cancer in the blood vessels in Blender 2.78c. Firstly, I created the network of blood vessels using this addon. Then, I created a simulation of the cancer with the UV Sphere growing in time (using keyframes on the Scale property). The problem is that this growing ball penetrates through the blood vessels, while I want to simulate the collision between the growing cancer and the blood vessels, which results in something like squeezing these vessels.

After some research I think that the blood vessels should be modified by the Soft Body, while the growing sphere should be modified by the Collision, but I'm still not able to simulate the collision between these two objects.

Here is my blendfile without any Physics. Thank you for your time.
This is not at all a "physically accurate" simulation by any stretch, but it may be able to approximate the desired effect with a bunch of modifier trickery using a Vertex Weight Proximity and a Cast modifier.



Use the Vertex Weight Proximity to make a vertex group weight vary according to the distance to a random object, in this case a "cancer ball", then use said vertex group to drive the influence of a Cast modifier set to Sphere.

You can then dynamically adjust the size of the "cancer sphere" (and shape too) to influence the distortion of the blood vessels