Day 4

I did more research and tests today on the cracking. I found another way of doing cracking by using a cellular crack node. it works the same way as how a texture map is used to create the crack. Below is the link from sidefx about it:

http://www.sidefx.com/docs/houdini10.0/nodes/vop/cellcracks

And I followed a tutorial that teaches me how to set it up:

http://www.sidefx.com/docs/houdini8/content/base/tutorials/fm_08_guide_shading_1012996.xml

Below is the screenshot of how it looks like after I tried it:

Mr Ron also helped me fixed the problems and look through all the issues that I raised on my blog yesterday.

1: The jumping while cracking problem

The problem is that there is overlapping geometry caused by the polyWire width being too big. I made it smaller. Mr Ron helped me add an expression so that the crack will grow bigger as the animation plays through. Mr Ron also helped me increase the divisions of both the ground and the polywire divisions.

Below is how it looks:

2: Ground Crack from the odforce forum.

Mr Ron explained to me roughly what is going on in the entire hierarchy.

This is how the crack looks:

And the hierarchy:

The crack is generated using a L-system crack. The crack is then re-imported it in as a geometry file. The crack lines is then split into 2 groups using a delete node. The main reason of that is first to fix the point numbers and then color it using a point node. Then fusing it together into one again. And using a point node again to generate some randomness into the crack lines. The rest of the hierarchy is more or less same as the original L-system crack hierarchy.

How to remove crack lines from a pre-fractured geometry:

Mr Ron showed me how I could remove crack lines from a pre-fractured geometry using a proxy object.

Firstly, We did a test fracture below:

A proxy geometry is used:

And a switch node is used to switch between the proxy geometry and the fractured geometry.