Modeling Diving Knife Tutorial

STEP 3 – HANDLE

In this part naturally we will go through handle creation. Again, we will use the same approach. First, create a base form and then using various operations we will make details on that base object. So, lets get started. We will start tracing out the sections from Front viewport, then after we are finished, we will rotate it. First, I’d create a symmetry line. Then start working on one half, then it, if needed the parts of lines I don’t need, and then using command with Average Curves option on smooth out the transitions between curves.

Outlining the blueprints

Outlining the blueprints

and with 3 units as radius lower straight line and outer curve: Ok. Next we need to explain something. The two curves (one ellipse and one curve – yellow ones) are needed, but they also need to be trimmed and joined with the two curves that touch them. So, Copy (with InPlace option) these two, and hide for now.
Copy with InPlace option

Copy with InPlace option

We will trim the originals with two curves: Now, using command match lower curves to the trimmed ones: Now, using , mirror all curves using that straight line as symmetry line: Now, we must the lines on the symmetry line, and for that we will use Average curves option in command, and when you’re done just use :
Section curves done!

Section curves done!

Now, select all section curves and using we will start the rotation axis on one end of this symmetry line, and from Top viewport we will rotate by 90 degrees.
Rotate section curves

section curves

Using command move all the sections to their places using blueprints as reference.
Place section curves

Place section curves

After you have positioned all the sections the right way, we need to create two curves from Front viewport to define our shape. Use Mid and End points on section curves so your curve is touching them.
Rail curves

Rail curves

Using command make a surface out of these curves:
Base form

Base form

New, lets create another curve with command from front viewport following the curve on the blueprints: You know what to do next. the surface with the curve (from Front viewport).
Trim surface

surface

Now, we need to explode this curve with command.
Explode this red curve

this red curve

We will get four segments out of this one, and we need to adjust two bottom ones. Using command show the control points and move them so they touch the intersection with closed curve and edge of surface. So for that naturally you will need to have Int OSnap option ON.
Explode and match

and match

Now, we need to one curve. We will split it with the surface:
curve to split

curve to split

You will get two parts of that split curve:
Two curves we need next

Two curves we need next

Using command, we will create two curves. We will click just three times for each curve to define them. So for start we will click on the ends of two yellow lines and on the dot. We’ll do the same for the opposite side:
Two simple curves

Two simple curves

Ok, you’ve created these, and now we need to create a curve out of surface edges. Click on the surface, and run command. Ok, now this curve needs to be split into two pieces:
Curve we need to split

we need to split

We need to split the yellow curve with the red ones. So, select the yellow curve, and run command and click on the three red curves:
curves

curves

Using that split curves, we will create a surface with NetworkSrf command and with the help of all yellow curves on the image below:
NetworkSrf

NetworkSrf

Now, you can that surface, and hide everything except those two. And turn on the blueprints layer again, we’ll need it now.
Hide everything

Hide everything

Now, trace the wavy curve from the blueprints and Copy it:
Wavy curves

Wavy curves

Using upper curve, the two surfaces:
Trim the surface

the surface

Now, using some OSnap and brain we will put one on the lower wavy curve:
Point on Intersection

on Intersection

Let me explain what just happened here. Since we know that Int OSnap option means cursor snapping on the intersection of two curves, those curves actually don’t have to intersect in 3D. Only in 2D. So, from Fron view, they seem to be intersecting, and placing a on that intersection in the Perspective viewport we will see where that point will be placed. It can be placed on either curve. So, by just slightly moving your mouse it will snap on one then on other curve. Then just click to create a on the wavy curve (this is all done from Front viewport, it is handy to have a perspective viewport ONLY visible so you can check on which curve the point will be created) After that, using that we will trim that wavy curve: For the other end of that same curve we will do some trimming also with the curve which actually intersects our curve in 3D. So no problems there, just trim from Perspective viewport:
Trim the red part (click on the red side of the yellow curve)

the red part (click on the red side of the yellow curve)

Ok, now we will adjust that curve and move its end to the surface end. Using command we will show the control points and move the last one:
Move control point

control point

Ok, this isn’t really gonna be ok, because we need way smoother transition. Why the hell this happened? Well, as you noticed there is one more control point very close to the last control point. And that makes the curve like this. What we need to do now is delete that control point. Just select it and hit key.
That is one much nicer curve

That is one much nicer curve

Using we will create one more curve: When you create this curve, you will need to its ends to the edges of this blue surface. Just make sure you don’t have Average Curves option in command checked. Ok, now we need one more curve. But on the other side. We will use this yellow (on the image below) curve and split it with two surfaces:
This curve

This curve

Split with these two surfaces

with these two surfaces

This is what you will get. Note, this one yellow curve is actuall two curves, so you will need to them: Ok, now using NetworkSrf command we wil create a surface between two curves we just created, edges of two surfaces and one “rail” curve.
NetworkSrf

NetworkSrf

Lets all surfaces now finally. Next step would be to close this surface into one solid. First lets go to the end of the handle, and using PlanarSrf select ALL edges on the back and create a surface:
PlanarSrf

PlanarSrf

Using command we will go to the other side of the handle end extrude a bit according to the blueprints. So if you have your blueprints layer turned off, turn it on.
Extrude

Extrude

This extruded surface will be into four parts, you can those parts with rest of the handle surfaces.
Joined surfaces

Joined surfaces

Using DupFaceBorder command we will make a curve border out of inner surface of the blade: (it is possible you will get two rectangles one by the other, you can then just trim the mid line and join them, but I would suggest just using PolyLine command trace the Ends and corners on that Face) After that, we need to Offset this rectangle by 1 unit. And then, using command and Rounded option make a rectangle using this one:
Rounded rectangle

Rounded rectangle

Now, why in the world we did rounded rectangle? Well, we will make a transition from handle which is pretty round to the blade back which is pretty sharp edged. That way we will get weird transition on the surfaces too. But if we have both sides a bit rounded there won’t be any sharp edges on the surface. Using command on the handle surface we will get closed curve: Now, isolate (aka hide everything else but) two curves. The one just made and the other one is rounded rectangle. Using command and OSnap End, Mid and Perp options create four lines starting from the rounded rectangle to the closed curve.
Lines

Lines

Using NetworkSrf command create a surface from these curves:
NetworkSrf

NetworkSrf

Now, all handle surfaces, and using command close it into one solid.
Closed solid

Closed solid

Using command make a round edge on the back of the handle with 0.8 units as radius: Next we will make top handle details. We will create one and then Copy it according to image below:
Lines

Lines

Now, using command we will project those lines onto the handle surface from Front viewport.
knife_92

Projected lines, now curves

Next, with command make pipes out of projected curves. For the radius use 4units.
Pipes

Pipes

Now we gotta end those pipes with spheres. With command make spheres centered on the ends of curves and use radius of 4 units.
Spheres

Spheres

Ok, now that we got our spheres, we need to join them. But with command. Then, using command make holes:
Nice surface :D

Nice surface :D

We can now use to smooth the edges, but, and that is a big BUT, that doesn’t work every time. You can try, I did, and it didn’t work. But it is a good practice to try it first because you might get away with it and save some time. If it doesn’t work, then you are stuck with pipe method. That is, create a pipe through the edges, split the surface with this pipe, and using some surfacing command create a surface to fill that gap. So, lets first create pipes of radius 1unit. Don’t forget to click on ChainEdges option before selecting any edge because these edges are shattered in a bunch of them… You can try using Autochain option after that ChainEdges option. It is very handy too.
Pipes

Pipes

Using command split our handle surface and delete pipes and the parts pipes split.
Holes

Holes

Using Blend command we will make a curve that connects two edges: Ok, let me explain this last step. What you need to do is start Blend command, then click on Perpendicular, and then click on one edge (having Quad option in OSnap is good thing) and click on that edge where you find Quad snap. Next, again, click on Perpendicular, and then click on other edge, and there find where quad osnap is, and there click. Using command you need to create curves out of edges:
red curves

red curves

Using command make some surfaces, and then join them:
Handle object

Handle object

Lets make a hole in the handle for the string or something. Go in front viewport and create a circle with 5 units as radius. Offset that circle by 2 unit to inside (I moved it a bit from the edges):
Circles

Circles

the surface with bigger circle:
Trim surface

surface

Using create a surface out of two edges and one smaller circle:
Loft: use Normal settings

: use Normal settings

those surfaces, and using , fillet the edges with 0.8 unit as radius. Ok, now lets move a bit up, and make another detail. Select ellipse and Offset it (from Right viewport) by 1 units towards inside:
Offset

Offset

Extrude the red ellipse according to our blueprints:
Extrude

Extrude

Ok, start command, and now using STrack in toolbar, and Quad and Int option in OSnap, hover over two quad points in Perspective viewport, and in Right viewport click on the intersection of two STrack lines. There is another way of doing this without STrack. Just using PlanarSrf create a surface, and with AreaCentroid on that planar surface the command will automatically create a in the center of that planar surface. Easy, huh? Now, move that point away, and offset the surface edge by 3 units.
Offset

Offset

Now, with command make a surface out of Edge, and . Please note, you will have to adjust the spacing between each to get smooth tip where the point is: those two surfaces, and using fillet the edges with 0.8 as radius: Using command just close this polysurface into one solid. Great, you are almost done. Almost. There is one last detail on this handle. Go to Front viewport and trace the curve according to the blueprints:
Curves

Curves

Ok, now you will need to handle surfaces, and join only these. The rest you can hide:
Part of surface

Part of surface

Using command mirror that curve using horizontal line as mirror axis. And with command with Average Curves option checked. Using the same method with putting the on intersecting curves which are actually not intersecting in 3D we make a point on our curve. That point needs to be Mirrored:
Points

Points

the curve with Points, and create a between start and end of that . curve and line. Using Offset, offset that curve towards inside by 1 unit:
Offset

Offset

Using , project these two curves from Front viewport. Using command, trim the surface between two curves:
Trim surface

surface

remaining surface from top viewport by 1 unit towards inside handle object (move both surface, and a curve that lies on the edge of that surface:
Move the surfaces

the surfaces

Using command make two lines on these tho isolated curves:
Lines

Lines

Again, make two lines, starting from corner of inner closed curve, and ending Perpendicular to the outer curve: Using create one surface:
Another two lines

Another two lines

Again, using make another surface: Ok, now we need to fill that triangle gap with some surfaces too. We will do that with command.If you get into some problems, the big curve.
Triangle EdgeSrf surface

Triangle surface

these surfaces:
Join surfaces

surfaces

Using PolyLine command create one closed polyline:
PolyLine

PolyLine

that line so it is positioned in the middle of this surface:
Move from front and top view

from front and top view

Extrude this curve with like on the image below (use BothSides=Yes options and Extrusion height is 3 units)
Extrude

Extrude

Ok, now using we will create a hole in our surface. But first, make sure your Normals point to outside.You will check that with command, and if the normals are towards inside, you need to flip them with command.
Dir command

command

Do this for the opposide side, or this. And these surfaces:
Join these surfaces

these surfaces

Using command, create a flat surface like on the image below: the handle surface with this flat surface:
Finish

Finish

So, after applying some different Auxpacker environment maps you get your self a knife
Final

Final

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12 Responses to “Modeling Diving Knife Tutorial”

  1. Brian Lake says:

    AWESOME tutorial! Haven’t seen any other tutorials with this much detail!

  2. Ivan says:

    thanks Brian, I appreciate it ;)

  3. Keke says:

    Looks a lot like Ragde’s diving knife.

  4. Ivan says:

    It is. If it is “his” design.
    I’m not really teaching design here, rather just modeling in Rhino.

  5. Robert says:

    What dimensions do you use and what version of rhino is this?

  6. Ivan says:

    I used centimeters, but those measures aren’t absolutely accurate, just a reference. Rhino version is v4.0 for all tutorials on this site.

  7. brad says:

    is it possible to use background bitmap instead of pictureframe? for some reason pictureframe just draws a frame and there is no image. do you know why?

  8. Ivan says:

    sure is. you can use background bitmap. As for the image not showing in pictureframe, search the forum, there have been couple of similar questions. I’d guess it might be problem with drivers. But than again, I might be wrong.

  9. Dioniso says:

    Excelent tutorial. Thank you!

  10. Gianluca says:

    Great tutorial but i have some trouble with the first sweep 2 rail for handle. i get some strange surface result. may i send you an image by email to check what is the problem?
    thanks in advance

  11. Ivan says:

    go to http://www.rhino3dhelp.com/forum/index.php?board=11.0 and open a new thread with your image attached.

  12. gnob says:

    first of all thank you for this awesome tutorial..,, second is to cast a newbie question.. how can I view the image after I make a picture frame?? it seems no bitmap image or jpeg Appeared after the operation…pls…help… if I’m going to use background image it will appear ,but if I;m going to use picture frame it won’t appear. only a rectangular line appeared….. as this tutorial instructed is much easy to use picture frame than background image….. pls…help….Much appriciated your help and respect..

    regards

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