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marchermitte
10-03-2009, 11:29 AM
Hello!
I'm having troubles riging a tentacle that has a chainsaw spinning along Its middle. I can set up thread tank easily with the morph trick from proton but :

-All the blades are not the same. There are 2 different blades linked by 2 hinges. (So Spline clone and morph won't work)

-I need the setup (once spinning) to deform with the tentacle and look like It's embeded in It.

I thougt about morphing a polychain and animate It THEN use meta link but It doesn't work too well so far.

Any advice will be welcome!

Thnks

Marc

SplineGod
10-03-2009, 03:11 PM
Do you have a concept drawing of how this is supposed to look?

marchermitte
10-03-2009, 05:22 PM
Hello Larry!
Well, That's the only sketch I got from the director. (This is an europeen very low budget independant prod. I'm sure you guessed It!)
I'm thinking of using DP motion nodes to stick each piece manualy to the proper point ID on the polychain. Then have the tentacle bones affect the polychain (use bone from) and why not try a bit of soft body on the top...

What do you think?

marchermitte
10-03-2009, 06:30 PM
Aaargh! Works well for the point cloning and Proton's morph trick (the one from the tank thread) makes the polychain morph forward just fine BUT the blades don't align to the normals (or path align if you prefer) whatever input I try... I guess It makes sense as polychain don't have normals, do they? What node could I use to force the blades to align (at least the pitch) with their motion?

marchermitte
10-05-2009, 01:23 AM
Ok! This is what is missing: a spot info where you can choose what object's normal you want to use to align the pitch of another object (in my case the chaissaw blades) OR an item info including the item's normal direction info.

Any one's got an idea what I can do to align the blade's pitch to the tentacle's normals? Expression maybe?

pooby
10-05-2009, 03:06 AM
I'd do it a simpler way.

If you just make it one object, you can use the morph trick to get the blades to appear to spin.
Then save out an mdd of that. (and the scene)
Load the mdd in with the DP pointer node, set to before bones.
Then add bones and animate the tentacle. This will give you both effects in one.

If you need to re-adjust the spin, just open up the first scene and save over the mdd. It will update immediately in the other scene, as the mddpointer node reads directly from the file, not a ram cache ( for ease keep 2 copies of LW open)

Basically with this method, you're using 2 scenes and a workaround to make a modifier stack for deformations. You can layer up as many scenes as you like.

The only very minor problem with this is that the blades will be deformed by the bones, but I very much doubt that it will be noticed.

marchermitte
10-05-2009, 03:22 AM
RIGHT! I forgot you can deform MDD additionaly with Denis MDD node and bones! I'll give It a try right now!
Thanks!

marchermitte
10-06-2009, 05:49 AM
Well, I works without the need to bake the MDD scene. Straight morph + bones... the only problem I had was with the displacement map from Zbrush (tentacle)... As I merged the blade and the tentacle as one layer, the displacement was wrecking the blade. I just added a weight map to isolatre the displacement to the only tentacle!

Thank you! i was looking for such a complicated solution... which could still work if we had the possiblility to use one mesh normal to align another one (motion node editor)

dandeentremont
10-06-2009, 11:07 AM
I really really really would like to see the finished video of this :)

marchermitte
10-06-2009, 12:14 PM
I'll post something asap, I'm also doing a silicone tentacle to interact with the actors during the shooting, so I'm not progressing too fast with the 3D aspect right now. The silicone tentacle has to be on set first...

Nangleator
10-09-2009, 02:31 PM
Tentacles with chainsaws beats sharks with friggin laser beams any day.

SplineGod
10-09-2009, 02:54 PM
Onstead of morphing the chainsaw teeth along the bones try a proxy obect and then mdscanning that. Hardlink the chainsaw teeth to that.

Speaking of sharks and chainsaws you cant make this stuff up sometimes... :)
http://onlygoodstuff.files.wordpress.com/2008/10/helicoprion23d.jpg

shrox
10-09-2009, 03:45 PM
Hello Larry!
Well, That's the only sketch I got from the director. (This is an europeen very low budget independant prod. I'm sure you guessed It!)
I'm thinking of using DP motion nodes to stick each piece manualy to the proper point ID on the polychain. Then have the tentacle bones affect the polychain (use bone from) and why not try a bit of soft body on the top...

What do you think?

The "studio" isn't HOF in Cornwall is it?

rod chambaud
10-15-2009, 02:34 AM
Well, I works without the need to bake the MDD scene. Straight morph + bones... the only problem I had was with the displacement map from Zbrush (tentacle)... As I merged the blade and the tentacle as one layer, the displacement was wrecking the blade. I just added a weight map to isolatre the displacement to the only tentacle!

Thank you! i was looking for such a complicated solution... which could still work if we had the possiblility to use one mesh normal to align another one (motion node editor)

hello,
for the problem of the displacement, you can do like that :
-in the displacement node, use a scalar layer instead af an image node
- in the scalar layer, use a image layer for your displace and below use a gradient layer with 0.5 value (it's the midle gray who is the zero displacement value for the Zbrush map)

dmack
10-15-2009, 10:24 AM
Wow, this sounds like a technical nightmare! I'd love to see how it's solved and the result as dandeentremont says!