Caterpillar software track

caterpillar software track
By Alain mathez.

https://www.foro3d.com/attachment.ph...1&d=1245946320

Like a lot of people, y have plenty of 3d ideas in the head, and most of the time i begin by directly drawing something in Blender. And like a lot of people, y know this is not a really god method, but i do all the same because i am todo lazy todo follow a better way.

Two weks ago, y was on a wellness wek-end with my girl friend. Thre days without any computer, hell or paradise? Well, without computer, but not really without Blender, because i could not get some of the ideas out of my mind. So i just had todo relax my body and let my brain choose between no-Thinking and b.2.48a. Guess what, y tok a Pen and a paper, and began todo draw some sketches. The best part in that story is that i had a lot of time todo grind the Project, before i could finally start todo build some objects in Blender. The ideas where numerous and growing every minute, i had already a list of problems and some solutions and Many derivations and alternatives.

Once bak at home, y tried todo do some critical points in Blender, and i submitted the unsolvable knots todo the legendary famous blenderclan (http://blenderclan, tuxfamily.org).

Note for the beginners (like me, sometimes) : try todo reduce your problem todo its simplest state todo find solutions. Open a new Blender file, with just the things you ned todo tackle the problem, and experiment with it. If you are unable todo find a solution, you can ask about it at blenderartists forum, explain the case and maybe give them the file. If you are a bit Lucky, you Will receive a lot of suggestions. Be careful not todo ask todo Many things at one time, the answers Will probably be lesser.

Definitions
Here you can se some fundamental definitions for Understanding what we can do with this tool todo improve the time of checks and verifications.
Well, enough said, lets get on with the Project. The main criteria are:

• doing animations with only one ipo (the one ipo research attitude : oira), lol, this name just make me laugh myself.
• when not posible, than as few as posible ipo research attitude : afapira)
• in the oira or afapira serial, we are starting with oing the whels of a vehicle staying on the flor (Mesh) with constraints doing a caterpillar software track, with dynamic inertia no addition of Python scripting, y am not yet a experienced in it (pydrivers are allowed)

Use modifiers and constraints from Blender 2.48a.
1. Layer 1 : the flor
Open a new Blender file, deleete all objects, select only layer 1 (1), switch todo top view (Numpad 7), add a Mesh plane (space, Mesh, plane), in Edit Mode (tab) select (RMB, shift+RMB) and deleete (x, 1) the 2 upper vértices, select the remaining Edge (a) scale it 20x (s, 20, enter), subdivide it 21x (w, 2, number of cuts :21).

https://www.foro3d.com/extras/tutori...erpillar/1.jpg

Select the vértices on the positive part of the x axis (b, LMB+mousemove), and hide them (h).

https://www.foro3d.com/extras/tutori...erpillar/2.jpg

Switch todo front view (Numpad 1) select the two middle vértices, switch todo the proportional edit tool (o), select random fallof, move the vértices 1bu along the z axis, having all the vértices in the select circle (g, z, mousewhel).

https://www.foro3d.com/extras/tutori...erpillar/3.jpg

https://www.foro3d.com/extras/tutori...erpillar/4.jpg

Switch todo top view (Numpad 7), reveal the invisible vértices (Alt+h), select all the vértices (a, a), extrude 2bu along the y axis (e, 1 y, 2, enter).

https://www.foro3d.com/extras/tutori...erpillar/5.jpg

Select all the vértices (a, a), recalculate normals outside (Control + N), swtich todo object mode (tab), add a modifier Subsurf (Control + 2).

https://www.foro3d.com/extras/tutori...mg-00300t1.jpg

https://www.foro3d.com/extras/tutori...mg-00300t2.jpg

Rename the plane in flor and make it smooth.

https://www.foro3d.com/extras/tutori...mg-00350tm.jpg

2. Layer 2 : the projections
Select only layer 2 (2), switch todo top view, add a Mesh plane and modify it todo obtain 10 Edges from 1bu (blender unit) on a straight line, place it on x=5, y=0, z=10, give it the name projectionflor and watch of the center on the object.

https://www.foro3d.com/extras/tutori...img-00450t.jpg

In Edit Mode, go todo the panel enlace and material (f9), add a vertex group (new), name it pr1, select only the first vertex on the left, press assing. Add a vertex group (new), name it pr1b, assing todo this group only the second vertex, then make the same for pr2, pr2b, pr3, pr3b. Pr6.

https://www.foro3d.com/extras/tutori...mg-00500tm.jpg

3. Layer 3 : the hooks
Keping layer 2 active, select layer 3 (shift+3), switch todo front view, add an Empty (space, empty), name it pr1, place it exactly on the same place as the first vertex from projectionflor, using the Control key todo Snap todo the grid (g, Control + mousemove). If the Empty doesnt have his z axis pointing up, chek in the user preferencias that the button aligned todo view is not enabled.

https://www.foro3d.com/extras/tutori...mg-00550tm.jpg

Add an empty, Snap it todo the grid on the same position as the second vertex, name it pr1b. Go on with pr2, pr2b. Pr6. Verify in top view that the position of the empties is correct on the y axis todo. In the panel draw (f7), show the name of the diferent objects on layers 2 and 3.

https://www.foro3d.com/extras/tutori...mg-00600t1.jpg

https://www.foro3d.com/extras/tutori...img-00650t.jpg

https://www.foro3d.com/extras/tutori...mg-00600t2.jpg

Select the Mesh projectionflor (RMB), switch todo Edit Mode (tab), select only the first vertex on the left (RMB). Staying in Edit Mode, select the corresponding Empty pr1 (Control + RMB) and create a hok on the vertex (Control + h, 2).

https://www.foro3d.com/extras/tutori...img-00700t.jpg

Then select the second vertex (RMB) and the second Empty (Control + RMB), create the hok (Control + h, 2), and so on todo the last empty. Now when you are finished, if you select one vertex and move it (g+mousemove), the corresponding Empty Will follow.

https://www.foro3d.com/extras/tutori...img-00750t.jpg

Well, that was just todo be sure that the setup is working, so dont move any vertex for the momento (Esc). Now the first trick, switch todo front view (numpad1), show the first layer (shift+1) todo se the Mesh flor, select the Mesh projectionflor, go todo the panel modifiers, add a modifier Shrinkwrap, set the parameters and enjoy the result.

https://www.foro3d.com/extras/tutori...mg-00800t2.jpg

Guess what, you have todo do the same for all the other vertex groups, but dont panic, when you click on the button copy in the modifier, you get todo copy all the attributes automátically, the only change you have todo make is todo the vgroup:pr1b, pr2, pr2b. Pr6). Now if you move the Mesh, you can se the empties following the flor. Pretty col, isnt itú.

https://www.foro3d.com/extras/tutori...img-00850t.jpg


4. Layer 4 : the Path
Show only the layer 4 (4), front view (numpad1) add some curves Bézier as landmarks todo position the curve Nurbs circle which Will be the Path of the caterpillar track. Because we dont ned 3d curves, it is necessary todo turn the curves around the x axis. Show the panel transform properties set the rotation for Rotx. And dont forget todo give names todo all your objects.

https://www.foro3d.com/extras/tutori...g-00900t1m.jpg

https://www.foro3d.com/extras/tutori...mg-00900t2.jpg

Note for the lazy people (like me, sometimes) : try todo Snap most of the control points from the Path pathcaterpillar on the grid (zoom around a bit if necessary) because son you Will have todo align Bones and empties on every control point of the Path. So it is easy todo do it with an extreme precisión where every object has his place on the grid.

https://www.foro3d.com/extras/tutori...g-00950t1m.jpg

Note for everyone (like me, sometimes) : ensure that you have a round length from your Path when youve finished designing it. For example, 50, because the caterpillar track Will be easier todo configure with (for example) 50 links, having every 1bu width.

https://www.foro3d.com/extras/tutori...g-00950t2m.jpg

Select all the vértices, go todo the panel curve tools (f9 when the curve is in Edit Mode), set the order u todo 3, and attribute todo all the vértices a weight of 1.

https://www.foro3d.com/extras/tutori...g-00950t3m.jpg

Note for the pressed people (like me, sometimes) : it is important todo draw the curve pathcaterpillar like a slak rope, because when the caterpillar moves, the track Will tighten. But remember, its not elastic, so the length must be kept constant.

The Path must look like a slak rope now because it Will look like a tight rope son.

https://www.foro3d.com/extras/tutori...img-01000t.jpg

https://www.foro3d.com/extras/tutori...img-01050t.jpg

5. Layer 5 : the constraints
We are going todo configure a lot of constrained empties. This system Will help us todo position the Stel frame of the vehicle, and todo deform the future armature which Will itself control the curve pathcaterpillar.

Show layer 3, 4 and 5 (3, shift+4, shift+5), add an empty, name it positionframe1, set its size as 0.5 in the panel enlaces and material, give it the Empty pr1 as parent (RMB on positionframe1, shift+RMB on pr1, Control +, enter), and move it 1bu above pr1. Do the same with positionframe2 (parent = pr3b), and positionframe3 (parent = pr6).

https://www.foro3d.com/extras/tutori...mg-01100t1.jpg

https://www.foro3d.com/extras/tutori...mg-01100t3.jpg

https://www.foro3d.com/extras/tutori...mg-01100t3.jpg

Add a Mesh plane, name it averageframe, modify it todo obtain 3 vértices on a straight line, with every vertex on the position of positionframe1, positionframe2 and positionframe3. Hok each vertex todo the corresponding empty.

https://www.foro3d.com/extras/tutori...mg-01150t1.jpg

https://www.foro3d.com/extras/tutori...mg-01150t2.jpg

Switch todo object mode, add an empty, name it orientateframe, place it on positionframe2, select the Empty orientateframe (RMB) and the Mesh averageframe (shift+RMB), switch todo Edit Mode (tab), select all the 3 vértices (a), and define the vértices as parent from the Empty (Control +, enter).

https://www.foro3d.com/extras/tutori...img-01200t.jpg

Now if you show the layer 2 (shift+2), select the Mesh projectionflor, and move it along the x axis, you can se that the Empty orientateframe follows the Mesh averageframe, but where the Mesh flor in layer 1 (hided) goes up, orientateframe goes up side do, having the z axis pointing downwards. To correct this, Simply add it as a constraint copy rotation on positionframe1, influence 0, and a trackto (Control + t, 1) on positionframe3. So you have 2 choices todo test later, just play with influences.

https://www.foro3d.com/extras/tutori...img-01250t.jpg

https://www.foro3d.com/extras/tutori...img-01300t.jpg

Switch todo side view (Numpad 3), add a Mesh plane, name it softframe, go in Edit Mode (tab), and rotate the plane around the y axis (r y, 90, enter). Select only the 2 upper vértices, merge them (w, 5, 3, enter), select all (a, a), subdivide (w, 1), and move all 1bu up (g, z, 1, enter). Set the parameters in the panel software body (f7, f7).

https://www.foro3d.com/extras/tutori...mg-01350t1.jpg

https://www.foro3d.com/extras/tutori...g-01350t2m.jpg

https://www.foro3d.com/extras/tutori...mg-01400t1.jpg

https://www.foro3d.com/extras/tutori...g-01400t2m.jpghttps://www.foro3d.com/extras/tutori...img-01450t.jpg

This method is not mine, you can read about it here. http://www.blendernation.com/2008/02...era-shaquíng/
And you Will find the full description herer http://blenderartists.org, http://blenderartists.org/forum/showthread.php?t=116699
Gracias you yoyofargo.

Add an Empty at the origin from softframe, name it softdynamicframe, and give it the 3 central vértices from the Mesh as parent.

https://www.foro3d.com/extras/tutori...img-01500t.jpg

https://www.foro3d.com/extras/tutori...img-01550t.jpg

So, when the Softbody Will move, the Empty softdynamicframe Will receive an angle of the movement. This angle Will be copied todo move parts from the future armature.

Add an Empty angleframe 2bu above orientateframe, define orientateframe as the parent of angleframe. Add a constraint copy rotation from softdynamicframe todo angleframe, leave only y and infuence 0.1.

https://www.foro3d.com/extras/tutori...g-01600t2m.jpg

https://www.foro3d.com/extras/tutori...mg-01600t1.jpg

Select the curve pathcaterpillar, and give it the angleframe as parent. Now if you move the Mesh projectionflor, pathcaterpillar Will follow the slope of the flor. If you rotate the Empty softdynamicframe around y axis, pathcaterpillar Will follow the rotation.

Hey, Grab a drink, its not finished yet. Add an Empty centermidwhel, child of angleframe, add an Empty IK Targetmidleft and an Empty IK Targetmidright both child of centermidwhel. Iktargetmidleft and IK Targetmidright must be placed on the corresponding vértices from pathcaterpillar.

https://www.foro3d.com/extras/tutori...img-01650t.jpg

Add an Empty centerfrontwhel, child of angleframe. Rotate it -90 grados around z axis (r, z, -90, enter). This special orientation Will be useful for a future IK constraint.

https://www.foro3d.com/extras/tutori...img-01700t.jpg

This Empty Will have todo turn in the other bien round of angleframe. To do the magical trick, we ned another Empty pivotfrontwhel, child of angleframe, and a constraint transformation on pivotfrontwhel. The target object of the constraint is softdynamicframe.

https://www.foro3d.com/extras/tutori...mg-01750t1.jpghttps://www.foro3d.com/extras/tutori...g-01750t2m.jpg

Centerfrontwhel Will receive a copy rotation constraint from pivotfrontwhel.

https://www.foro3d.com/extras/tutori...mg-01800tm.jpg

Now if you rotate softdynamicframe, you should be able todo se something like this.

https://www.foro3d.com/extras/tutori...img-01850t.jpg

Vaya, no sea-sicknessí then do the same for the right side of the force.

https://www.foro3d.com/extras/tutori...mg-01900t1.jpghttps://www.foro3d.com/extras/tutori...mg-01900t2.jpg

https://www.foro3d.com/extras/tutori...mg-01950t1.jpghttps://www.foro3d.com/extras/tutori...mg-01950t2.jpg

6. Layer 5 : the armature
Add an armature on layer 6. Remember that each bone starts and ends on a vertex from the curve pathcaterpillar (you might se some exceptions on the picture below). Origin of the armature is the position of orientateframe, and parent of the armature is orientateframe todo.

https://www.foro3d.com/extras/tutori...img-02000t.jpg

When the armature is designed, in Edit Mode select all the Bones (a) and recalculate bone roll angles (Control + N, 1).

Its time todo add IK constraints. Armature is in object mode. Select the Empty centerfrontwhel (RMB), select the armature (shift+RMB), switch armature todo pose mode (Control + tab), select the bone which already pointing on the empty, add the constraint todo active object (shift+i, 1).

https://www.foro3d.com/extras/tutori...mg-02050t1.jpghttps://www.foro3d.com/extras/tutori...g-02050t2m.jpg

Dont forget todo disable the stretch button, we ned a constant length. The option root lets the bone follow the rotation of the target, and you, Lucky people, have already set the orientation of the target centerfrontwhel in part 5, didnt you?
https://www.foro3d.com/extras/tutori...mg-02100t1.jpghttps://www.foro3d.com/extras/tutori...g-02100t2m.jpg

What else? The IK for the middle whel.

https://www.foro3d.com/extras/tutori...mg-02150t1.jpghttps://www.foro3d.com/extras/tutori...mg-02150t2.jpg

And the last, but not least, the constraints for the flor.

https://www.foro3d.com/extras/tutori...mg-02200t1.jpg

https://www.foro3d.com/extras/tutori...mg-02200t2.jpg

https://www.foro3d.com/extras/tutori...mg-02250t1.jpg

https://www.foro3d.com/extras/tutori...mg-02200t2.jpg

Have you twigged? Vaya, by the way, you must add in layer 3 an Empty prepr1, child of pr1, and a postpr6, child of pr6.

https://www.foro3d.com/extras/tutori...mg-02300t1.jpg

https://www.foro3d.com/extras/tutori...mg-02300t2.jpg

https://www.foro3d.com/extras/tutori...mg-02350t1.jpghttps://www.foro3d.com/extras/tutori...mg-02350t2.jpg

https://www.foro3d.com/extras/tutori...mg-02400t1.jpghttps://www.foro3d.com/extras/tutori...mg-02400t2.jpg

Show the layers 5 and 6, rotate the Empty softdynamicframe (+ and -90°), what do you se? Armature is deformed but not stretched? Goal reached. Well, in fact not completely. The IK for the middle whel is only efective when it stretches a Little bit.

https://www.foro3d.com/extras/tutori...img-02450t.jpg

Note for the experts (like me, maybe one day) : if you find a better bien todo use the IK constraint, without any stretching, with a full constant length for the complete chain, por favor share some tips as how you achieved it.
7. Layer 7 : the hooks
This one is only for pleasure. On each vertex of the curve pathcaterpillar place an empty. Names are hokpath. Hokpath.0xx. Well, on the picture bellow the names are still in french, but its todo late todo translate this in detail, and im not ready with the extra work, so por favor translate for me hokchenille = hokpath.

Select the armature go in pose mode (Control + tab), select an Empty (Control + RMB), select the corresponding bone (shift+RMB), make the bone parent from the Empty (Control +, 1).

https://www.foro3d.com/extras/tutori...img-02550t.jpg

Do i have todo be precise, its necessary for each empty?
When its done, show layers 3 and 7, select the curve pathcaterpillar, go in Edit Mode, select 1 vertex (RMB), select the corresponding Empty (Control + RMB), make the hok (Control + h, 2).

https://www.foro3d.com/extras/tutori...img-02600t.jpg

And one more time, im afraid thats necessary for each empty. But if youre a god pianist, it doesnt take you a long time todo Perform.

Now we start a special step: making the track enlaces following the Path. This Will be always be only an appróximation. Why? Because i know of only two methods and both are not real.

First method: origin of the enlaces are on the Path, then the joints are todo Distant on the Little curves.

https://www.foro3d.com/extras/tutori...img-02650t.jpg

https://www.foro3d.com/extras/tutori...img-02700t.jpg

Second method: origins of the enlaces are working with a trackto constraint, but the joints are todo close on the Little curves.

https://www.foro3d.com/extras/tutori...img-02750t.jpg

https://www.foro3d.com/extras/tutori...img-02800t.jpg

Well, first method seams todo be more imprecise, but faster todo set up. Well take this one for now, with narrow track links. The illusion should be enough.
8. Layer 8 : the enlaces
Model a simple enlace about 1bu (x axis), 2bu (y axis) and 0.5bu (z axis). You could do it with a deformed Cube, or like me, a bit more complex.

https://www.foro3d.com/extras/tutori...img-02850t.jpg

https://www.foro3d.com/extras/tutori...img-02950t.jpg

https://www.foro3d.com/extras/tutori...img-02900t.jpg

https://www.foro3d.com/extras/tutori...img-03000t.jpg

https://www.foro3d.com/extras/tutori...img-03050t.jpg

Select the enlace (RMB) select the curve pathcaterpillar (shift+RMB), make the enlace follow the curve (Control +, 2). Clear the rotation (Alt+r, enter) and the origin (Alt+o, enter) of the enlace. If necessary, re-orientate the (r) enlace todo align it along the curve. Make sure that the curve is configured with Curvepath, Curvefollow and pathdist OFS in the panel curve and surface.

https://www.foro3d.com/extras/tutori...mg-03100t1.jpg

https://www.foro3d.com/extras/tutori...g-03100t2m.jpg

If the enlace is not on the straight portion of the curve, select the curve, go in Edit Mode, select all. The only non-yellow Edge (not selected) is probably not in the middle of the straight portion.

https://www.foro3d.com/extras/tutori...img-03150t.jpg

Select one Edge in the middle bottom, erase it (x, 2), the problem should be solved. If the curve is open, close it (c).

Quit the Edit Mode of the curve. Select the enlace, make a duplicate (Alt+t), give it a timeoffset todo 1.00 in the panel Anim settings (f7).

https://www.foro3d.com/extras/tutori...mg-03200t1.jpg

https://www.foro3d.com/extras/tutori...g-03200t2m.jpg

With the duplicate method (Alt+a and not shift+a) you can modify a enlace, selecting each duplicate and modifying at the same time. So you do your test with a simple deformed Cube, and After the 50 enlaces are ready, you can tweak their appearance without doing the work 50 times.

Note for the smart people (like me sometimes, but not enough for this case) : there is maybe a magic trik with an array modifier or something like this todo add all the enlaces with just as few clicks. If you find it, por favor let me know.

You remember the round length of the curve pathcaterpillar? It was about 50, but the enlace is about 1bu width, so you have todo do the same again 48 times, Alt+a, timeoffset: 2.00, Alt+a, timeoffset: 3.00.

https://www.foro3d.com/extras/tutori...img-03250t.jpg

9. Layer 9 : the whels.

This part is left as an exercise for the Reader. I Will just show you my layer as example. I began with the first whel, upper left, and the others are modified and scaled copies.

https://www.foro3d.com/extras/tutori...img-03300t.jpg

Parent of the whels are on the layers 3 and 5. Frontwhel is a child of centerfrontwhel, middlewhel is a child of centermidwhel, rearwhel is a child of centerrearwhel, florwhel1 is a child of pr1, florwhel2 is a child of pr2, florwhel6 is a child of pr6.
10. Layer 10 : the master and the guide.

On layer 10 add two empties. The first one, master, must be placed at 0 on the x axis, 0 on the y axis, and 20 on the z axis. The second, guide, must be placed at 0 on the x axis, 0 on the y axis, and 10 on the z axis. Guide Will then receive a copy location constraint from master, only for the x-axis.

https://www.foro3d.com/extras/tutori...mg-03400t1.jpg

https://www.foro3d.com/extras/tutori...g-03400t2m.jpg

Guide is the parent of the Mesh projectionflor on layer 2, and guide is the parent of the Mesh softframe on layer 5.

Now if you move the Empty master along the x axis and above the Mesh flor, you should se the Ensemble following the surface of the flor.

https://www.foro3d.com/extras/tutori...img-03450t.jpg

Is Sliding not enough? Dont give up, youve already done the greatest part. Go todo the animation screen Layout (Control + ) or from the menú.

https://www.foro3d.com/extras/tutori...mg-03500tm.jpg

Select the curve pathcaterpillar (on layer 4), in the window ipo curve editor select the ipo type todo Path.

https://www.foro3d.com/extras/tutori...mg-03550tm.jpg

If there is no ipo curve in the window, add a vertex near from the origin of the axis, (Control + LMB) and another a bit further (Control + LMB). Specify the interpolation mode as linear (t, 2), and the extend mode as cyclic (e, 4).

https://www.foro3d.com/extras/tutori...img-03600t.jpg

https://www.foro3d.com/extras/tutori...img-03650t.jpghttps://www.foro3d.com/extras/tutori...img-03700t.jpg

Open the transform properties box, edit the ipo curve (tab), select the first vertex (RMB) give it the coordinates in the box.

https://www.foro3d.com/extras/tutori...mg-03750tm.jpg

https://www.foro3d.com/extras/tutori...mg-03800tm.jpg

The second vertex has x coordinate 50 because this is the length of the curve pathcaterpillar. If you dont choose cyclic for the ipo curve, the enlaces Will do only one portátil along the Path.

Now the mysterious miraculous pydriver. Write Blender. Object. Get(master). Locx *(-1)
Tadam.

https://www.foro3d.com/extras/tutori...mg-03850tm.jpg

https://www.foro3d.com/extras/tutori...mg-03900tm.jpghttps://www.foro3d.com/extras/tutori...mg-03950tm.jpg

If the enlaces move in the wrong direction, you can inverst the ipo curve (like \ \ \ and not / / /), or add a *(-1) factor at the end of the pydriver.

Showing only the layers 8 and 10, select the Empty master and move it along the x axis. Impressive? Wait todo se the whels. Select the frontwhel, select the ipo type object, select roty (LMB), click on the add driver button in the transform properties box, click on the Snake and write, Blender. Object. Get(master). Locx *(3.05).

Note for the mathematician people (not like me, im afraid) : i have absolutely no idea why the factor is 3.05, but i find it god in testing. It depends naturally on the teth on the whel, but in my case 50 / 12 = 4.16. So, who knows why?
Apply the same tweak for the other whels. You can of course re-use the ipo curve from frontwhel for the rearwhel, with only one ipo curve for the six florwhels, and one for the middlewhel if its size is not the same as florwhels.

https://www.foro3d.com/extras/tutori...img-04000t.jpg

Do you remember the oira or afapira acronymsí well, the ipo speed for the Path is a straight line and doesnt really count. So the only object todo animate with an ipo curve is the empty, master. In frame 1 (shift+) select master, Insert a keyframe for location (i, 1), go todo frame 51 (¿), move master along x axis, and Insert a keyframe for location (i, 1). In the ipo window you can select and deleete the ipo locy and locz, and/or you can edit and adjust jsut the ipo locx.

https://www.foro3d.com/extras/tutori...img-04050t.jpg

If the Mesh softframe acts strangely, go in the panel collision and click on free cache.

https://www.foro3d.com/extras/tutori...mg-04100t1.jpg

https://www.foro3d.com/extras/tutori...g-04100t2m.jpg

Pay attention todo the value for end in the same panel if you do an animation longer than 250 frames.

If the Mesh projectionflor acts strangely, edit the Mesh flor, select all, and extrude a tiny Little bit (e, 1, z, -0.01). If no there result, try todo deleete the Subsurf modifier, or try todo apply it.

https://www.foro3d.com/extras/tutori...img-04150t.jpg

Note for the debug warriors (maybe like me, y dont know) : if you find why the Shrinkwrap modifier does this Jump, por favor let me know how todo correct it.

Remember you can set the fine tunning with the influence of the copy rotation constraints from centerfrontwhel, angleframe, centerrearwhel, and you can choose between copy rotation and trackto for orientateframe.
11. Layer 11-13 : the shock absorber.

Let us do a pistón, a bellows and a Spring, on the layer 11: an armature.

https://www.foro3d.com/extras/tutori...img-04200t.jpg

https://www.foro3d.com/extras/tutori...mg-04250t1.jpghttps://www.foro3d.com/extras/tutori...g-04250t2m.jpg

https://www.foro3d.com/extras/tutori...mg-04300t1.jpg

https://www.foro3d.com/extras/tutori...mg-04300t2.jpg

https://www.foro3d.com/extras/tutori...mg-04350t1.jpg

https://www.foro3d.com/extras/tutori...mg-04350t2.jpg

On the layer 12: some empties, todo use as the target for IK or trackto (the choice is yours).

On the layer 13: the objects. At first the pistón, block high has a trackto in the direction of block Low, and block Low has a trackto in the direction of block high.
(editor note: this introduces a cyclic dependency which Blender has trouble resolving. If posible, it is best todo avoid such setups altogether todo be safe. However, if such setups are used, be aware that some lag may occur in some parts of the rig, making it unsuitable for RenderFarm use).

https://www.foro3d.com/extras/tutori...mg-04400t1.jpg

https://www.foro3d.com/extras/tutori...mg-04400t2.jpg

https://www.foro3d.com/extras/tutori...mg-04450t1.jpg

https://www.foro3d.com/extras/tutori...mg-04450t2.jpg

Now the bellows. Blok left and block right are now tracking each other like a pistón. The bellows Will ned a stretch todo constraint.

https://www.foro3d.com/extras/tutori...mg-04500t1.jpg

https://www.foro3d.com/extras/tutori...mg-04500t2.jpg

The effect is simple but the illusion is perfecto.

https://www.foro3d.com/extras/tutori...img-04550t.jpg

https://www.foro3d.com/extras/tutori...img-04600t.jpg

.as long you dont switch todo the side view. If the bellows are deformed (dont ask me why) just adjust the z size (s, z, mousemove).

https://www.foro3d.com/extras/tutori...img-04650t.jpg

https://www.foro3d.com/extras/tutori...img-04660t.jpg

If the orientation of the bellows is wrong, show its axes in the panel draw (in the object buttons). Rotate all the vértices in Edit Mode, with the cursor at the origin of the object and pivot mode set todo around the cursor.

Finally the Spring. This one Will be vertical. The trackto constraint neds todo have an axis pointing upwards, so in this case there is a conflict between the target directions and the up pointer. We Will use a bone, with a IK constraint todo orientate the up and Low blocks, and each block Will have a copy rotation of the bone. Almost as easy as for the pistón.

How todo model a Spring? Easy, but we want todo animate it. Add a plane, place the cursor at its center, in front view let only an Edge and a vertex. Select all, and press screw in the panel Mesh tools.

https://www.foro3d.com/extras/tutori...mg-04700t1.jpg

https://www.foro3d.com/extras/tutori...g-04700t2m.jpg

Erase the cylinder and kep the Spring.

https://www.foro3d.com/extras/tutori...img-04750t.jpg

Select all, go todo the menú Mesh > scripts > Edges todo curve. The script did a copy from the Mesh, and we have now a new curve. Edit this curve, select all the vértices, in the panel curve tools click on Nurb, endpoint u, order u: 3, weight 1, set weight. Go bak todo object mode. Add a curve Nurbs circle, name it springbev, reduce its size. Select the curve Spring (not the Mesh, you can deleete this one), give springbev as bevel object in the panel curve and surface. Nothing happens, so edit the curve Spring, select all, set the Radius todo 1 (w, 4, enter). Special gracias todo zeauro from the blenderclan for this trick.

But the wire of a Spring is not a hollow tuve, so we ned another Nurbs curve as taper object. Note that the size of springtaper is 0.1 in object mode.

https://www.foro3d.com/extras/tutori...img-04800t.jpg

https://www.foro3d.com/extras/tutori...mg-04850t1.jpg

https://www.foro3d.com/extras/tutori...g-04850t2m.jpg

https://www.foro3d.com/extras/tutori...img-04900t.jpg

Resize a bit the upper and the lower part of the Spring, you know, todo obtain something like, a Spring.

Note for the tired people (like me, its late) : lo siento just a bad joke.

Construction, from top todo bottom.

Springblockh, child of fixeabsorber1 (the main Empty for the absorber).

https://www.foro3d.com/extras/tutori...img-05000t.jpg

Receives a copy rotation constraint retargeting boneabsorber2 from armatureabsorber. Remember, a trackto constraint is not posible because object has todo track vertical down.

Empty centerspringh, child of springblockh.

https://www.foro3d.com/extras/tutori...img-05050t.jpg

Curvespring, child of centerspringh.

https://www.foro3d.com/extras/tutori...img-05100t.jpg

Empty scalespring, child of centerspringh.

https://www.foro3d.com/extras/tutori...img-05150t.jpg

Centerspringl, child of springblockl.

https://www.foro3d.com/extras/tutori...img-05200t.jpg

Springblockl, child of the Empty centerwhel2.

https://www.foro3d.com/extras/tutori...img-05250t.jpg

Bonespring from armaturespring, child of centerspringh.

https://www.foro3d.com/extras/tutori...img-05300t.jpg

Bonespring has an IK constraint on centerspringl and stretch enabled. The high (local y axis) of bonespring is precisely equal todo the deformable part of the Spring. Add a copy-scale constraint (on y-axis only) todo the Empty scalespring. Scalespring is oriented like bonespring of course, and placed at the begining of the deformable part of the Spring. Select all the vértices from the deformable part of the Spring, select scalespring, make a hok. Select the lower un-deformable part, select centerspringl, make a hok.

So, like you se, rigging a dynamic Spring is not todo dificult. But once again this method is not mine, y derived it from http://blenderunderground.com/2008/0...ig-in-blender/ simplified it (i guess) and improved (i hope). So, dude, all you have todo do is.already done.
Well, thats it. Add some mecánico elements todo complete the absorber. Of course a tanque have no such absorbers visible and fragile, but 3d is not the real world, so. Why notú.

https://www.foro3d.com/extras/tutori...img-05350t.jpg

12. The challenge.

Now if you want todo make a vehicle moving on a bumpy Ground, you Will face bigger problems. The second caterpillar track cant ride for itself. Both must have the same tilt and kep the distance between them constant, because this distance is the vehicle.
Well, who can do it better, is more simple and faster? It is posible, im sure. But i didnt already found the solutions. And dont forget the oira or afapira principle.

If youre better than me (im sure its posible, because i succed on doing this almost every day ;-) and find a better way, or if you have questions, remarks, ideas, suggestions fel free todo contact me at Alain@bktr, ch.

My favorite lenguaje is french, but i can decode english (por favor simple words only und auch ein bisschen deutsch (da noch mal bitte nicht zu komplizierte wörter verwenden).

Have fun.
13. Example files.

In the example file caterpillarsofttrack, blend you Will find the object described in chapter 1 todo 11, a tanque downloaded from http://dmi, chez-alice, fr and a lot of cameras fixed todo each important part of the caterpillar. Some objects have still a french name, lo siento.

In the example file tracklinkappróximation, blend there are the 2 methods described just before chapter 8 todo make enlaces follow a Path. Other ideas todo do this?
In the example file límitepathpydriver, blend there are a lot of test with ipo speed and pydriver you can play with.
14. Gratitude.

Special gracias todo the blenderclan, meltingman (my spiritual master), traven (the man who knows everything i ignore) zeauro (i have questions, he has answers), and todo my honey coralie who slept and watched the televisión alone for two weks while i wrote this. And thank you todo every people who makes Blender growing.

https://www.foro3d.com/extras/tutori...llar/final.jpg

By Alain mathez. www.blenderart.org.

-- IMÁGENES ADJUNTAS --
https://www.foro3d.com/attachment.ph...hmentid=108689