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mc_axe
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Mesh cut through

Post by mc_axe » 14 Apr 2017, 00:43

I need to 'project' a mesh on a specific axis to create a hole on a second mesh.
So if i have a bullet and second mesh is a cube the result i need is just a cube with a cylindrical hole.
But then it gets more complicated if my "bullet" is a complex mesh with any orientation.

Example imagine the light is -x
Image

The outline of a model on a certain axis (curve or smthing) would be handy as well.

Any ideas?

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Mathaeus
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Re: Mesh cut through

Post by Mathaeus » 14 Apr 2017, 10:43

Perhaps the best way, theoretically, it is to start from resulting mesh, it's cube here. Projection could be done in ICE by ray-casting toward cutter, or even by render mapping a shadow of directional light ( let's say the one that's present in screenshot). This makes the correct ''projection'' (while something like SI Slice Polygons won't). From that, projection phase, should be possible to make a cut and delete polygons, or extract a curve. Don't know is there already available an ICE topology ''cutter by weightmap value'', anyway.
In any case, I think it should be easier to start from another, usually planar mesh, - instead of 'projector'.
The renderer "turtle" used by this scene, is not currently available. The "turtle" renderer will be used instead.

Pooby
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Re: Mesh cut through

Post by Pooby » 14 Apr 2017, 11:41

Try this compound (add the ICE tree to a null).. First object is the Subdivided grid to cut and second is the object shape to cut. It works on the y plane and its not perfect but might give you a starting point
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mc_axe
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Re: Mesh cut through

Post by mc_axe » 14 Apr 2017, 18:06

Thx for replies :)
Pooby wrote:Try this compound (add the ICE tree to a null).. First object is the Subdivided grid to cut and second is the object shape to cut. It works on the y plane and its not perfect but might give you a starting point
Hey Pooby a raycast on a dense grid is not a bad start indeed, unfortunately cant get it to work (nub with ice here)

I just added the compound to a null with only 2 meshes in the scene grid and cylinder, result grid dissappears
If i switch order cylinder disapears

I entered the compound and i see
Image
is tht ok? :?
--
@Matheus i actually scaled a mesh to z=0 to hack it in to something planar but too many components overlaping, and i couldnt find a way to makes somehing useful out of it. b-(

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mc_axe
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Re: Mesh cut through

Post by mc_axe » 14 Apr 2017, 19:28

Figured a manual way still looking forward to something more automated like ICE.
Hidden content: [ Show ]
Example we have two meshes nicknamed "bullet" and a "wall" and we want to shoot the bullet in axis Y in order to cut through the wall mesh.

scale the "bullet" mesh to Y=0
select manually the outline (including outline edges that overlap/intersect)
curve extract from edges
curves to mesh, check lines can intersect (if needed)
Manually weld the intersecting edges to intersection points
Apply thickness and now this is the our cutter mesh that we can boolean difference with the wall

*Only tested with a low poly "bullet" mesh with no holes

Pooby
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Re: Mesh cut through

Post by Pooby » 15 Apr 2017, 09:08

Oh sorry that must have referenced my own compounds. You just need to get point position to fill in the missing connections.

So getdata. Pointpositions. And plug into the yellow connector/s on the right
(Which is the Multiply node on the first and 'array average' on the second)

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mc_axe
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Re: Mesh cut through

Post by mc_axe » 15 Apr 2017, 16:14

Thanx alot Pooby! :ymhug:

Cut hole raycast is awesome, thanx for sharing! I spend half hour only observing how the grid polygons update while im changing orientation scaling moving etc.
I was expecting a pixelized result this is great!

Image

Cheers

Pooby
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Re: Mesh cut through

Post by Pooby » 16 Apr 2017, 00:33

You're welcome. Thanks for the challenge. It was fun to figure out how to do it.

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ActionArt
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Re: Mesh cut through

Post by ActionArt » 10 May 2017, 23:18

Hi mc.axe,

I'm totally lost in ice. It can't seem to add the missing nodes correctly and nothing happens so I must be missing something obvious. Would you be able to share your simple test setup?

Much appreciated if you can, this looks very interesting.

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mc_axe
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Re: Mesh cut through

Post by mc_axe » 11 May 2017, 00:45

Hey ActionArt
Here is the scene, (i hope the compound is in there)
If you want to try new objects, dont forget to click the compound (ice tree of null) in order to go through the pick session to get right names.
--

Edit

@Pooby if you looking for more challenges with cuts and slices :ymhiro: take a look on this thread, I hope you find it interesting.

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Draise
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Re: Mesh cut through

Post by Draise » 11 May 2017, 01:18

I have to try this!

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ActionArt
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Re: Mesh cut through

Post by ActionArt » 11 May 2017, 15:53

Thanks for uploading! I'm sorry however I only have 2014 so the scene won't load. Perhaps a screenshot of what you did if you have time? Thanks so much for your help.

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mc_axe
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Re: Mesh cut through

Post by mc_axe » 11 May 2017, 20:15

I only added these 2 nodes
So you can do Get data -> write PointPosition or just copy/paste the 'Get Point Position' node in the bottom right
Image

Make sure Grid and null is in default possitions (with no transforms), + make your grid like 30% larger area than the expected hole.

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ActionArt
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Re: Mesh cut through

Post by ActionArt » 11 May 2017, 21:17

Thanks, that worked. I had the nodes right but the possition of my null was wrong. Thanks again!

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mc_axe
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Re: Mesh cut through

Post by mc_axe » 11 May 2017, 21:20

No problem glad it worked for you :-bd