Halftrack wheel - boolean divide fails & alternatives

# 1 12-06-2015 , 10:51 PM

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Halftrack wheel - boolean divide fails & alternatives

Hey guys, first post here so thank you all for having me.

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A quick introduction, I am a graphic designer/illustrator who is gearing up to use Maya in his workflow. To start off I decided to model a more modern German halftrack I concepted a while ago. Due to it's blocky shape it's mostly a hard surface project and it should give me an opportunity to learn.

I'm trying to cut deep circular holes into the rubber track of the front wheels using boolean divide. unfortunately, this operation makes my mesh dissapear. After googling I understand the geometry is probably too complex to perform booleans now. Is there a way around this? Or are there any other options?

Here is my original concept:
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Progress so far:
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Thanks in advance!

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# 2 13-06-2015 , 01:56 AM

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Hi Vince, welcome!

Which version of Maya are you using? In 2015 and higher, booleans are a lot more forgiving than in previous versions.

There are a bunch of reasons why the operation might fail. First, try deleting the history of the objects before performing the operation. If that doesn't work, try another boolean method. Does it still fail? Another thing you could try is adding more divisions along the length of the cylinders, and then trying again.

Imagination is more important than knowledge.

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# 3 13-06-2015 , 07:52 AM

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I have responded to quite a few posts in the past on Boolean operations. If you do a search you might find something helpful. As ND suggests always delete history before doing the Boolean. Also you want to avoid long thin polygons, so you should add divisions along the cylinder of both the wheel and the cutters. (this is what I would guess is causing the operation to fail).

Also use symmetry to your advantage. You can that wheel in half along z and quarter it along y and x and only have to work on 1/8 of the part.

After performing the boolean, if you intend to smooth you will have to do some clean up so try to align edges in the part being cut and the cutters to minimize the post boolean cleanup work.

I am recording a camtasia video to demonstrate and will post a link shortly.

Here is a link to an example of doing the Boolean difference to create the track gear.

https://youtu.be/8vhPHB_diQc

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

Last edited by ctbram; 13-06-2015 at 09:01 AM.

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# 4 13-06-2015 , 08:42 AM

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Hi Vince, welcome!

Which version of Maya are you using? In 2015 and higher, booleans are a lot more forgiving than in previous versions.

There are a bunch of reasons why the operation might fail. First, try deleting the history of the objects before performing the operation. If that doesn't work, try another boolean method. Does it still fail? Another thing you could try is adding more divisions along the length of the cylinders, and then trying again.

Originally Posted by NextDesign

I have responded to quite a few posts in the past on Boolean operations. If you do a search you might find something helpful. As ND suggests always delete history before doing the Boolean. Also you want to avoid long thin polygons, so you should add divisions along the cylinder of both the wheel and the cutters. (this is what I would guess is causing the operation to fail).

Also use symmetry to your advantage. You can that wheel in half along z and quarter it along y and x and only have to work on 1/8 of the part.

After performing the boolean, if you intend to smooth you will have to do some clean up so try to align edges in the part being cut and the cutters to minimize the post boolean cleanup work.

I am recording a camtasia video to demonstrate and will post a link shortly.

Originally Posted by

I am using the 2015 version. Thanks for the advice! I'll work on these when I get back from my day job tonight.

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# 5 13-06-2015 , 08:47 AM

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There is a link to a camtasia video in my post above. It's still processing but should be available soon.

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

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# 6 13-06-2015 , 11:15 PM

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Bram, thanks a heap for that video! I learned to control my wireframes and ended up experimenting with a bunch of wheel making techniques tonight. I started pasting my segment onto another tire idea and came up with this funky 'steel-plated' wheel idea. I'm going to run with it for now while I work on other parts of the model.

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I have also started cleaning up the mesh of the base of the halftrack. There will be many more nights until this baby is done. I'll get back to you guys if I have a question I can't google myself out of, again thanks!

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# 7 14-06-2015 , 01:59 AM

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Looks good! You could now go in and delete the extra edges on the front of the tires, as they don't add any detail. (They're also on a planar area)

Also, take a look at your normals on the stand-in geometry for the back tracks. Those black areas are caused by issues with the normals. Normals>Set to Face should suffice for this.

Imagination is more important than knowledge.

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# 8 14-06-2015 , 08:42 AM

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Are there any specific rules to mesh cleanup work? I've noticed I can't just go delete any edge I feel is in the way, as often the fold in the faces remains as if the edge was still there.

What is a normal? The flat back tracks will be deleted soon, I'm going to try and add a crazy segmented track with detail.

Stay patient and trust your journey

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# 9 14-06-2015 , 03:12 PM

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1. when you delete edge do not just hit the delete key. This leaves the verts and so the shape will not change and you will have orphaned verts in the middle of edges. I use marking menus so ICannot recall where the "delete edge" command lives in the tabbed menus.

2. Normal refers the the direction of the outward facing side of a polygon. Faces have a side that faces out and reflects light and a backside that does not. Under lighting tab you can turn off two-sided lighting and see one side will become black. If you see black faces it usually means you have flipped normals. This can lead to non-manifold geometry if two faces are facing opposite directions and connected by an edge.

There is a cleanup command and under remove geometry I usually select - lamina faces, non-manifold geo, edges with zero length, faces with zero geo area.

You can also highlight faces with more or less then 4-side and non-planar faces which can help to find surfacing issues.

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

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# 10 14-06-2015 , 11:14 PM

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1. when you delete edge do not just hit the delete key. This leaves the verts and so the shape will not change and you will have orphaned verts in the middle of edges. I use marking menus so ICannot recall where the "delete edge" command lives in the tabbed menus.

2. Normal refers the the direction of the outward facing side of a polygon. Faces have a side that faces out and reflects light and a backside that does not. Under lighting tab you can turn off two-sided lighting and see one side will become black. If you see black faces it usually means you have flipped normals. This can lead to non-manifold geometry if two faces are facing opposite directions and connected by an edge.

There is a cleanup command and under remove geometry I usually select - lamina faces, non-manifold geo, edges with zero length, faces with zero geo area.

You can also highlight faces with more or less then 4-side and non-planar faces which can help to find surfacing issues.

Originally Posted by ctbram

I think I understand, so I need to delete the edge first and then the vertexes connecting to it? Or delete the edges and do the Cleanup Mesh command afterwards for the stray points?

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progress so far. I've done a first cleanup on the wheels as you guys mentioned and blocked out the mayor other shapes. Atm I have three mayor problems that I could not google my way out of

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The bottom of the front cockpit got axed during one of my cleaning runs, and now it's a huge face without edges. I tried Cut Polygon tool to 'recut' the edges but that jury rig won't work apparently.

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I'm also trying to create a belt shape to strap the grenade-like objects to those backpacks. I'm trying to work with curves but both options I can find through tutorials bug out like in the pictures. I haven't found a google solution to this problem.

Thanks for all your help and advice so far guys, I really appreciate you taking time out of your schedule. If you don't mind I will keep coming back to this thread for all questions I can not solve through searching. Every button I click creates three solutions and five more questions, it's both furstrating and exciting user added image

Stay patient and trust your journey

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# 11 15-06-2015 , 12:01 AM

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Hi Vince,

0) You can use the delete edges tool (Edit Mesh > Delete Edge/Vertex), which will delete the vertices as well, or you can select the edges and press the backspace key. This will leave the vertices, so you must remove them. I usually marquee-select over the area and press backspace. Note: if any vertices are connected by only two edges, that vertex will be deleted. See: https://download.autodesk.com/global/...elvert1NOT.png

1) You posted the same image twice. Can we see the problem?

2) Try lofting the curves again, but set the output type to polygons, the type to quads, and the tessellation method to general. Change the U and V numbers to get the necessary amount of edges.

Feel free to ask any other questions - we're here to help!

Imagination is more important than knowledge.

Last edited by NextDesign; 15-06-2015 at 12:04 AM.

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# 12 15-06-2015 , 03:23 AM

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To delete the edge and all the verts you can

1. select edges to be deleted
2. press shift-RMB and the pie menu will come up
3. select the "delete edge" option

[Imgur](https://i.imgur.com/V1vPueI.png)

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

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# 13 15-06-2015 , 08:23 AM

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Thanks for the advice, I'll try these when I get back from work.

Here is a new upload of the edgeless face at the bottom of the cockpit (front)
user added image

. Before the two front faces were also connected to this large face, I managed to fix that with Cut Polygon, but the bottom (here top) faces don't respond to the same treatment.

Stay patient and trust your journey

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# 14 15-06-2015 , 04:19 PM

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One way to fix that would be to delete it, then use the Append to Polygon tool under Mesh Tools. Then, click on one edge, and then the one you want to create the polygon to, and press enter. Repeat for all other edges.

Imagination is more important than knowledge.

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# 15 15-06-2015 , 06:52 PM

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One way to fix that would be to delete it, then use the Append to Polygon tool under Mesh Tools. Then, click on one edge, and then the one you want to create the polygon to, and press enter. Repeat for all other edges.

Originally Posted by NextDesign

As NextDesign said but instead of pressing enter use the "y" button to reuse last tool, should speed up the process a little............dave