Graphic PIZiadas

Graphic PIZiadas

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3D Animation, Examples: Christmas Tinsel [ Blogs experimental ] [ Blender ]

The Christmas tinsel is a braided strip “by” or “flat elongated elements” made with different materials (this, silver paper, Plastics); usually has a shiny appearance or monochrome; we use it as a decoration at Christmas; guides for different hanging Christmas decorations.

Modeling an object in Blender can be addressed with different editing techniques. In this case we use from curves to define their shape. We will approach the problem in three development activities:

  • Create a tube of great length and small diameter of the object form the basis.
  • Addto its surface “strips” or “by” that give it its characteristic shape.
  • Assign the material and define the characteristics of illumination for visual effect we seek.

Structural axis tinsel

Bezier curves can be easily edited to construct the path of tinsel.

We use a simple scene consisting of a cube and a corner, so also the object “Cube” need three objects “Plane” to the ground and the two walls.

The scene is unimportant so it is simplified in the example.

Generate tinsel guide

First insert a curva Bezier on the hub, similar to that seen in other object inncorporar: (with the cursor on the 3D, will press “space” and then :

Add->Curve->Bezier Curve”

The curve will serve to guide the tinsel on the object, we situate at a distance to reserve space for the fibers or hairs.

In version 2.49:

By selecting the curve and enter the mode “edition” objects have access to the tab “Curve and Surface”. Need to enable the option “3D” if we engage a Objeto, if the tinsel on a plane is not necessary, simplifying the shape of the curve.

Can also generate a 2D curve and subsequently use “lattice” or “armature” to guide the 3D space.

In version 2.6x:

Menu Object data

Menu Object data

Select the curve and access to the menu “Object data” to modify the parameters of the curve. The fields of action are similar in both versions, although changes available in the menu and in some cases the identification label.

By default the option is enabled “3D” so we can move freely in space points, curve adapting to our needs. Adjust both the points and the direction of the tangents at each to suit our taste.

Generating from the tube guide:

From Bezier curve can generating a tube, Need a new curve, in particular we can use a circumference of Bezier to link it in the field “BevOb:” (Command Object) that shown in Figure.

Both diameter (scale) as the circumference of the path of the Bezier curve forming the tube, are modifiable with their handlers.

While editing the tube, we can use a girth diameter which resembles the finished espumillón. Once the editing is reduced to the core diameter espumillón. the surface that is going to generate the “rope” or shaft that holds strips or hairs that cover. Is a small diameter, 10 times less than the length of the hairs. In our case we used 0.025 Blender units dimension to su.

The last step of modeling espumillón shaft consists of generating a surface on which situate fibers or strips “shiny hairs”.

The tube we have built is a mathematical representation based on Bezier curve and the circle that makes section.

Tinsel hairs

Blender used to generate hair meshes.

You need to convert the tube into a surface. It's a good idea to make a copy of the pipe object (Alt + D) and move (M) another layer if we make any subsequent amendment.

Once it has converted the “tube” a mesh operation is irreversible.

We will now have a set of triangular surfaces and have lost the ability to manipilación using Bezier points. In edit mode we see that instead of the control points Bezier Curve, We happened to have vertices of the polygon mesh, whose edition is more laborious.

To convert the object (tube) in a mesh (Mesh) select the object and will push the button Alt and then the key “C“.

Convertir a malla

Convert to Mesh

Particle System

Again change the way of generating the particle system, depending on the version you're using:

Version 2.49

Once converted into a polygon mesh, we can add a particle system to simulate hair. Select the mesh mode “Object” activate the “Particle buttons” to add (“Add New”) a new system of particles then configure.

We will show that the particle system is specifically hair generator (Hair).

This is done from the dial located on the new tab button “Particle System” that appear to add the new particle system.

The amount of hairs (Amount) are controllable by one variable that can change. A large number calculations slow, so it should be used with caution.

The main parameter is the length of hair, indicating that the speed is determined starting from the surface particles (are particles).

Speed “Normal” perpendicular to the surface. Itself solely increased that amount, see a picture too regular a pattern. We will provide a random value (Random) or tangential (So) and rotation thereof to “mess” elements.

400 by

4000 by

400 random hairs

Version 2.6x

Access to the menu for managing particle systems:

Add a new system with the button “+”

We will show that the particle system is specifically hair generator (Hair).

The main parameter is the length of hair, indicating that the speed is determined starting from the surface particles (are particles).

Speed “Normal” perpendicular to the surface. Itself solely increased that amount, see a picture too regular a pattern. We will provide a random value (Random) or tangential (So) and rotation thereof to “mess” elements.

Mode will activate “Advanced” to access some menus that are not active by default and you can adjust the values ​​mentioned.

We can add some rotation and tangential velocity to achieve the desired fill effect.

Both versions

This model we have developed allows us to obtain representations formed by fine hairs tinsel, in the next section will generate the most common and consists of “strips” flat small thickness and width. As an example of the results that can be obtained see the next picture. (Click to Enlarge)

Textures of the tinsel

In general behave like a shiny surface, with a high degree of reflection, whereby the inherent color will be less relevant than the surrounding.

To give some tinsel hairs superfíciea, replace these by “strips” rectangular.

Add the scene a “plane” to climb into the shape and size of the strip we want. This is important comment that the main direction of the strip corresponds to your axis “x”

Then, associate this “strip” system to display on the tab particle “Visualization”. First indicate that we want to replace the system of particles by an object (object) and we will enter your name in the space provided.

On Version 2.6x the menu for this functionality is in “Visualization”

Si la “strip” we have generated is not rooted in the global coordinate origin, this transformation or displacement will add to the hair, distorting the result.

Transformations have accumulated with absolute respect of each hair, creating the impression of “explosion” Object.

To accurately position the element at the origin “strip” we obtained by modifying our map, we can use the coordinate input window, we obtained by pressing “N“, with the cursor over a 3D window.

Modify the parameters affecting its location “Place” until they zero.

Under these conditions only fail us assign material properties the “strip” (plane) so as to perform a calculation “raytracing” for specular.

Indicate or activate in the material “Ray Mirror” and introduce a value of a 80% the available thanks to the scroll bar. Also add color if we want to have it.

The last step is to add lights are bright colors for multicolored reflections. Land use three centers each with one of the basic colors (R, G, B) indicating shadows are made by Ray tracing.

You can see some examples on page wallpaper (Wallpapers)

Other approaches

There are many ways to raise the model. We opted for a simple to implement and has continuity with the concepts presented in the blog about Blender. Depending on the approach to learning can be addressed in other ways, with advantages and disadvantages.

For example, not be the only, raises two approaches that are tailored to a medium level of learning.

  • Using a cylindrical surface whose shape is governed by the curve. An interesting alternative to avoid losing control of the curve, which serves as an object axis, and to maintain the ability to change by Bezier curve
  • Using a lattice for the transformation of a cylinder. Not recommended due to the difficulty of their “guided” continuous (latex) it is essential to simulate forms “threadlike” or very long (as is the case espumillón).

Collisions (update)

One detail that had not been discussed previously and you have asked me in the mail and comments is how to fix the tinsel seems to rest on the object, without penetrating inside.

The solution to this problem is to enable the calculating collisions between objects.

In the first image that illustrates the post have a bucket and on its upper face tinsel we have located some distance, but hair length can create interference in the contact zones.

We will activate “both elements” crash analysis; In object mode (Object Pulsando F7 or the button with axes) enter the physical mode by activating the “Physiscs button” and simply activate the button “Collision“. There is a set of parameters that allow you to adjust what we mean by “contact” defining minimum and maximum distances for this calculation, to explain to view this module. In our case we can accept the default values.

Version 2.6x

Again the interface differs slightly, standing the menu to add collisions in paragraph “Physics”

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