Animating wet concrete

[mattlester]

Hi all,
I'm working on a project that requires me to animate a hard edge object smoothing a lumpy soft surface. E.g. i.e. scraping wet concrete to a smooth surface, grading rough dirt with a bulldozer leaving smooth area behind, etc...
If possible I would also like to show the 'gathering' of the soft substance in front of the leading edge of the hard object as it is smoothed.

I thought of maybe using displacement maps on a subdivided plane, but I'm not sure how to leave a 'smoothed' trail behind the hard edged object using this technique in an animation.

I know there may be quite a few other ways to do this - PFX/hypervoxels, hard/soft dynamics, cloth dynamics, etc...

So any ideas would be greatly appreciated.

Cheers,

[ACLOBO]

one thing that sprang to mind was to copy those points and use them as HV emiiters. Have your soapy, goopy substance created at this leading edge and have the lifespan of these particles shortlived so that they are created and then disappear pretty quick. Add some turbulence to these emiiters (so they vibrate a bit) and I think you could have a pretty decent thing going.

-Adrian

[mattlester]

Thanks Adrian,
Good idea, I hadn't thought about the new lifespan options with hypervoxels - I think it's worth pursuing - particularly for the leading edge goopy stuff. I once used a similar technique on a small waterfall type water feature for the bubbling where the fall impacted the water surface - but without the lifespan stuff.

Still not sure though how to have the general area in front of the smoothing object look rough and bumpy, but have it look smooth behind the trailing edge.

Perhaps a particle collision of somesort on a large plane of hypervoxel points, with the scraping object pushing aside/forward the points in front, leaving an exposed smooth textured plane behind? Is that doable in LW? Haven't had a lot of experience in this type of thing - I do mostly arch.viz. I think it would have a big hit on render times though. For the large surface areas I would rather an option using just maps. Then use your HV idea just for the detail around the leading edge.

- Matt

[jeremyhardin]

what comes to mind for me is:

have 2 cement objects. a wet object and a smooth object.
make a box that trails behind the scraper with intertia using this method here:
http://vbulletin.newtek.com/showpost.php?p=310999&postcount=2
use this plugin, which acts as an animated boolean, on the wet object:
http://flay.com/GetDetail.cfm?ID=1809
so that where the streaming-behind-box is, the wet is hidden and the smooth is revealed.

just a thought.

[mattlester]

Thanks Jeremy,
Great idea! - the Shift boolean plugin is just what I'm after, along with your helpful pointers for the described technique.
I think when I combine what you and Adrian have suggested I will be well on my way. I greatly appreciate your input guy's!

- Matt

[Stooch]

One idea:

Bump + spec maps to simulate we concrete.

Add a secondary layer to the bump map that is flat ( try a gradient ) and play with the blending to smooth the bump map with that layer.

use object reference to move that smoothing layer with a null that is parented to your scraper. a displacement map might also help.

--------------------

Another idea:

2 flat planes.

top is smooth concrete. bottom is wet.

use a displacement on the bottom that pushes through the smooth concrete (make sure the displacement map is set to EDGE rather then tile).

use object reference that will move the displacement, exposing the grooved, edge along with the scraper.

play with the combination of the two ideas ??

[SplineGod]

Heres an example I created using techniques I cover on my displacement and endomorphs CDs.
This is done using two endomorphs to get the cement to smooth out and pile up in front of the blade. Im also using HVs where the cement sort of piles up and rolls in front of the blade. Im also not using any particles or dynamics. The scene uses two objects only: the blade and the cement.
http://www.3dtrainingonline.com/examples/cement.mov