Best/Fast approach for car wreck look (no sim needed)?

[catchyid]

Hello,

I need to deform a car geometry to quickly create crash like deformation (plz, see attached). Note, I don't need a full simulation, just the final shape. What is the best approach? I tried to deform some parts of the car mesh using turbulence/anti-aliased/mountain noise, but it did not look right! 

Another idea is to use vellum (or bullet with soft constraints) to simulate metals and hit the car by random objects, but I am hoping for something faster.

Any ideas?

Thanks,

Edited October 20, 2019 by catchyid

[Andrea]

Hello! Maybe you can try with manual sculpting of the damaged parts and then add on top the noise (I think I would go with worley and antialiased). You can also get extra details with the shader and painting cracks.

Doing a real simulation would be cool but between geometry preparation and setting up the simulation, you risk to lose a lot of time.

[catchyid]

Thanks Andrea  I have a huge set of cars and the goal is to test whether it's possible to produce their wreck automatically, hence cannot sculpt manually. I am trying metaballs and so far they produce better results than just turbulence/anti aliased noise (but still sometimes, they produce intersecting pieces!). Another idea is to create deformers with metal like deformation (this is step is manual though), but then apply these deformers anomaly ! will see  BTW, I've seen your car crash shot on youtube and it looks awesome

[Andrea]

For sure you can setup the main bending to be procedural and introduce more subtle details in the same spots with noises. 

Do not use just noises. In my previous experience with some "procedural destruction" (not with cars) I noticed that I got the best results by instancing a couple of objects with different scale on the surface (spheres/cubes with a low frequency noise), transforming them to very low resolution VDBs and using volumegradient to control the displacement of the surface. This way I was getting consistent and smooth deformations (no intersections). Later on, with a couple more nodes I've added a variation in the noise to the various main parts (in your case for example to the doors, body of the car ...). This last steps introduced some cracks that was very helpful in my case. Never tried with metaballs, maybe they are better  

If you have a lot of "extra" objects and details in your car, you should consider to create some sort of proxy geometry, deform this one and transfer back the deformation to the original car. It's going to be faster to deform and probably cleaner.

 

Thank you! I would like to make it again someday, I had no idea what I was doing at the time

Edited October 21, 2019 by Andrea

[catchyid]

Thanks Andrea, I got your idea until using volume gradient  Not sure If I understand that correctly, meaning: If I have a VDB and a mesh, should I boolean them? or use volume gradient then boolean?  

[Andrea]

What I mean is using it for knowing how far is the point inside the VDB and move the point accordingly.Of course you can also using booleans i you want to cut it 

[catchyid]

Thanks Andrea