Modelling a "cooler" for machine guns

[stefanino]

Hi to all!
Hope to post in the right forum, mine is not exactly a tutorial, i do not have the knowledge to tell other how to do something, let call it a suggestion about how to model a cooler for machine guns ( hope is the rght name:) )

I guess that there will be other hundreds way to model this, even though i have searched and not found anything about, but this is the way i have found easier for me, even is a little long to do, and of course all the suggestion about my way or other way to model it are more than welcome!!
Anyway the idea has come to me, after a friend, also here on MM has mailed me if i can help him to model this "cooler".

The way is this, involve polymodelling, array and shapemerge.

1) Build a cylinder with the dimension you need, with at least 18 segment, no caps.

2) Meshsmooth with 2 iteractions, to make the mesh very dense, so the holes will be as sharp as they can.

3) Draw a spline circle, in the size that you need.

4) Give an array to have as many circle/hole as you need.

5) Select one circle, convert to editable spline, and attach multi with the other, now you are ready to sharpmerge and make the holes in the cylinder.

6) Select the cylinder(mesh) apply a shape merge, pick up the circle( shape)

7) Click on the modify stack, you will have now an object called shape merge, convert to editable poly and clic on poligon.... and you will have all your circle shape on the cylinder highlited in red, press delete and you will have the first line of holes.

8) Now turn the cylinder for a new line of holes and follow the steps 6 and 7, than turn again and again step 6 and 7 until you have complete all the cylinder. That's it, you will have a nice cylinder all filled of hole to merge in your model.

As i said before, all the suggestions are more than welcome, maybe is not the best way, but you can get a good result, as you can see in the attachment.

I am really happy that i can give a little suggestion, after a lot of question and help i have had from the friend here, and i want to thank all of them for their kindness in their answers :)

Hope my little tutorial or better suggestion, can be useful.

Cheers guys!!
Stefano

[Pablo_nemesis]

Good idea making a tutorial, but i would rather A) go whit booleans ( ugly mesh , i dont like ugly mesh XD) or B) model all the barrel long and each hole in .. lets say low poly ( i mean quads, you know) and then meshmooth it might need 3 or 4 iltherations.
This way you get A) A decent looking finished model, not very high poly but ugly mesh or B) a rather quite high poly mesh but (if done right) superb looking and smooth.

Just one more thing,you can add a shell modifier to your finished mesh( the one in the pic) to make it more realistic.

p.s.: sry for languaje, not perfect english.

[cobra6]

indeed use boolean, cilinders and a shell modifier aterwards :)

Cobra 6

[stefanino]

Hi guys and thanks for the replaies!
Well i have forgotten to apply the shell modifer......
About boolean, i have not tried this because i thought that was better using shape merge, but i will try also with booleans, and any advice is more than welcome!!!!!!!!
Thanks!

[Skyraider3D]

Stefanino, I'm afraid your resulting model looks very messy, with lots of long thin edges, which wreck the smoothing.
The way I would do it, is to build a section of the barrel as a flat piece, so you have full control over the polygons and shape. Making sure the edges are aligned length-wise like the segments of a cylinder. Then rolling it up to a tube by applying a Bend modifier of 360 degrees to it. Be sure to compensate for the hole which gets squashed when bending (assuming in real life they're drilled and therefore perfectly circular in plan view).
It's an interesting 3D problem and a good idea you brought it to our attention.

[stefanino]

Hi Skyraider
well i am still experimenting this and i can see that a lot of vertices are coming around the hole, as usual with shape merge and also with boolean, and, maybe this is ok if the object is little in the render, means like a machine gun on a wing or a turret, but of course, if the object is something else, means bigger, this way is not the right.

I will try your suggestion about blending a plane or a very thin box, and see what will be the result.
About the hole, what could be your suggestion?
Chamfering a vertex different times until the shape of the hole is almost rounded and than apply meshsmooth( but in this way i think that is a little difficult to have the hole, before smoothing, with the right amount of faces, all at the same distance, to have a perfect hole, or bolean and than clean the mesh from extra vertex and extra edges before bending?

Also the diameter of the holes compared with the diameter of the barrel are important.
if the hole is littler than the the part of the curved surface, i think that will not be squashed too much, if it is bigger it will be squashed.
Sorry for the long post, but after time where i have not modelled so much, i want to improve my skills, trying to experiment on my own.

[Skyraider3D]

The way I did it, I drew a rectangle and an ellipse inside it. Attached the ellipse. Turned it to editable poly and started editing the edges so they all lay in the length.

For the dimensions of the hole (ellipse) you will need to do some maths though! :)


PS. MAX 8 comes with Power Booleans and I am pretty sure it can handle it much, much better.

[cobra6]

PS. MAX 8 comes with Power Booleans and I am pretty sure it can handle it much, much better.

MAX 9 that is :)

Cobra 6

[Skyraider3D]

Wasn't there a patch for 8?
I'm still on 7 myself, although at work we're expecting 9 soon...

[kiwi123]

I just model the whole thing in SubD, will end up looking perfectly smooth and not a lot of polys unless you need them at rendertime. I model one quarter piece, which takes around 10 minutes. Then duplicate and presto.

[cobra6]

Wasn't there a patch for 8?
I'm still on 7 myself, although at work we're expecting 9 soon...

Nope, SP3 and still nothing... I read it was MAX9, which also had better integrated mental ray.

I'm getting it in a couple of days, so I'm kind of curious ^_^

Cobra 6

[Skyraider3D]

I just model the whole thing in SubD, will end up looking perfectly smooth and not a lot of polys unless you need them at rendertime. I model one quarter piece, which takes around 10 minutes. Then duplicate and presto.

How you keep it round then? Show us a wire please :)

[kiwi123]

What do you mean with how do you keep it round ? You start of with a cylinder of course ! :lol:

[Skyraider3D]

You know what I mean :)
When you make a hole, you get pinching and the tube starts to look like a twig... How do you ensure the curvature is preserved around the holes and everything stays nice and circular in cross section?

In other words: show us a wireframe please :)

[kiwi123]

You do that by keeping the tension right. Think of the edges as little elastic bands, they need to counter the pulling force to prevent pinching. I'll try and dig up a wireframe tonight.

[kiwi123]

It's not entirely the same, as in, it's not a circular hole. Therefore it needs more divisions, but it shows what I mean. This is a part of the spit cannon.

[Skyraider3D]

Crikey. That hardly needed subdividing anymore! :)
I guess the main problems I have with my SubD meshes is that I try to make it do too much with too few polygons. See, I would try a 12-sided tube with 4-sided holes! :lol:

Thanks for the wire!

[kiwi123]

Believe you me, I tried with less but ended up with more trouble. The cannon on the spit are quite big and I needed it to look good.

[roshent]

Are there tri-polys in there or is it that the quad thing is just not visible on that wire ? Just wondering...

[Pink Mesh]

Personally, I prefer manually constructing my cooling sleeves.

1. Make a cylinder of the appropriate geometric resolution.
2. Make a circle of the appropriate geometric resolution.
3. Manually merge the circle into a section of the cylinder.
4. "Float" the section with the hole into another object.
5. Spin duplicate the hole and the cylinder's section.
6. Copy paste the perforated section until the proper number of perforations is achieved.
7. "Shear" the cooling sleeve into shape.

For an ultra clean mesh:
8. Merge the cylinder sections into the circular holes.

I will add pictures to further demonstrate my method, if anyone wants further information.

[Skyraider3D]

I think I lost you at step 4 :)
Pictures would be great.

[Pink Mesh]

"Manually Constructing a Cooling Sleeve in polygonal geometry."

By "Pink Mesh" (c) 2007, not to be reproduced without the express permission of the author. If you wish to host this tutorial or compile it, alone, or with other tutorials, in any way, please contact me for approval. You may print out a copy(s) of this tutorial for your own personal use, so long as the author is fully credited.

1. Make a cylinder of the appropriate geometric resolution. (32 vertices are used in this demonstration.)

2. Make a circle of the appropriate geometric resolution. (16 Vertices are used in this demonstration.)


3. Manually merge the circle into a section of the cylinder.

3. A For this operation I have locked the manipulation tool to move vertices only on the "Z" or vertical axis. The circle is then "Bent" to the cylinder's shape by pulling the vertices down, along the Z axis. (Pulling the vertices on a locked Z axis ensures that the circle will not deform during the process of blending the circle to the cylinder's shape.)


3. B Delete the horizontal edges along the first seven vertices of the cylinder. Once the area around the circle has been opened up, close the area around the circle by creating faces as shown. Once this is done, the circle is fully merged into the cylinder.


4. "Float" or separate the cylinder's section with the hole as a separate object.


5. Spin duplicate this selection. For the spin duplication you will need to spin duplicate the cylinder's section 5 times, over a 360 degree rotation. Make sure that you are spinning from the proper diameter center. Once the spin duplication is complete, add the necessary faces to the open areas. (The areas which are left open during a spin duplicate are not shown here.)


6. Copy paste the perforated section, horizontally, until the proper number of perforations is achieved. (Picture for the illustration of this step is unnecessary.)

7. "Shear" the cooling sleeve into shape. (For this operation I am using a lattice deform box, with the front end of the box scaled by .5)


8. Extrude the whole cooling sleeve and hide the inverse or external cooling sleeve.


9. Select each internal cooling sleeve ring and scale by .9. (Separately size each ring to avoid a collapse on the horizontal axis.)


10. Select each series of holes and scale by .9. (Separately scale each series of holes to avoid a collapse on the horizontal axis.)

If you wish to use sub surfing or "Turbo Smooth" make sure that you place a loop cut in each hole before applying the smoothing. Also be sure to delete the faces on the ends of the cooling sleeve.

[kiwi123]

Right, and now that with thickness and looking smooth.

[Skyraider3D]

Ah right, with "float" you meant "detach". Different terminology between different software packages.
Gotto agree with Kiwi though, that isn't not a perfect solution.

[Pink Mesh]

Tutorial updated. If anyone needs anything further explained, just ask.

[raf]

Perfect solution, IMO, would be:

1. open any CAD package (I use Solidworks)
2. go to sketch mode, draw circle and thin extrude.
3. in another sketch (plane perpendicular to the first one) draw another circle for hole and cut extrude
4. make appropriate pattern with cut hole featue

If you're anal enough cutout edges can be filleted with radius of 0,1 mm, for instance.
All parameters can be changed, later.
Also shape of the barrel and cutouts can be changed to any 2D shape (star, shamrock, flower, etc.) :lol:

Seriously, though. Good results could be obtained with tube of dense enough mesh and booleans (with some manual adjustments, of course). Plus some edge chamfering afterwards.
Kiwis subD looks great, but honestly it is hard to make fillets small enough in subD. If that part is in reality made of stamped sheet steel, those edges should be almost invisible (fraction of a millimeter).

The thing that could save us all a lot of time is making small fillets in render process instead of geometry. It is supported in one of new mental ray materials in Max9. Don't know about other software. I have dreamed of this kind of feature for ages, great for machined parts. Have had chance to try it and it can't do everything but works good on 90 degree edges just fine.

Just my opinion.

[kiwi123]

Well, you need a fillet for your highlight, thats it.

[raf]

Exactly, that is way it would be good to have it applied only in render process instead of torturing oneself by modeling something that should hardly be seen.

[Skyraider3D]

The thing that could save us all a lot of time is making small fillets in render process instead of geometry. It is supported in one of new mental ray materials in Max9. Don't know about other software. I have dreamed of this kind of feature for ages, great for machined parts. Have had chance to try it and it can't do everything but works good on 90 degree edges just fine.That's awesome news. I've wished for such a feature for years already! Just a render gimmick to "take off the edge" of hard edges. Sorry for the pun :lol:

[GreatHumpback]

The thing that could save us all a lot of time is making small fillets in render process instead of geometry.

In fact, such a tool has existed for ages in Max! It's a plugin from DDAG called f-Edge. It is intended to go on the Bump Map slot (a wrapper is provided for combining it with others bump-maps), and works really great! It has a good number of options (inverted curve, edge weights, noise, gradients). It can also be used on the diffuse slot to "paint" the edges.

More info at http://www.ddag.org/

[giant551]

A friend of mine did this a little while ago maybe this could help:)

http://www.pjpti.pwp.blueyonder.co.uk/tutorials.htm

[Skyraider3D]

In fact, such a tool has existed for ages in Max! It's a plugin from DDAG called f-Edge. It is intended to go on the Bump Map slot (a wrapper is provided for combining it with others bump-maps), and works really great! It has a good number of options (inverted curve, edge weights, noise, gradients). It can also be used on the diffuse slot to "paint" the edges.

More info at http://www.ddag.org/

Very cool, thanks for the heads-up!



Nice tutorial, Giant :)
I often work like that as well... model the holes, then model around them and delete the holes.