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Názorná ukázka

curve tools v Blenderu poskytují rychlou a jednoduchou cestu k vytvoření dobře vypadajícího vytaženého textu nebo loga. Nyní použijeme tyto nástroje k vytvoření loga dle náčrtku. Načrtnuté logo na obrázku je logo, které budeme vytvářet.

Načrtek loga

Nejprve musíme vložit náčrtnuté logo do Blenderu, abychom jej mohly použít jako podklad. Blender podporuje obrázky ve formátu TGA, PNG, a JPG. K vložení obrázku vyberte z nabídky 3D okna View >> Background Image... . Zobrazí se průhledný panel, přez který nahrajete svůj obrázek do Blenderu, jenž se v Blenderu zobrazí jako pozadí. Aktivací tlačítka BackGroundPic a užití tlačítka LOAD umístíte obrázek který chcete použít jako podklad (3D window settings.). Můžete si také nastavit "sílu" průhlednosti obrázku na pozadí pomocí Blend posuvníku.

3D window settings.

Get rid of the Panel with Esc or by pressing the X button in the panel header (Logo sketch loaded as background). You can hide the background image when you are finished using it by returning to the Panel and deselecting the BackGroundPic button.

Logo sketch loaded as background

Add a new curve by pressing Space >> Curve >> Bezier Curve. A curved segment will appear and Blender will enter EditMode. We will move and add points to make a closed shape that describes the logo you are trying to trace.

You can add points to the curve by selecting one of the two endpoints, then holding Ctrl and clicking LMB Template-LMB.png. Note that the new point will be connected to the previously selected point. Once a point has been added, it can be moved by selecting the control vertex and pressing G. You can change the angle of the curve by grabbing and moving the handles associated with each vertex (Bézier handles).

Bézier handles

You can add a new point between two existing points by selecting the two points and pressing W >> Subdivide (Adding a Control Point.).

Adding a Control Point.

Points can be removed by selecting them and pressing X >> Selected. To cut a curve in two, select two adjacent control vertices and press X >> Segment.

To make sharp corners, select a control vertex and press V. You will notice that the color of the handles changes from purple to green (Vector (green) handles.). At this point, you can move the handles to adjust the way the curve enters and leaves the control vertex (Free (black) handles.).

Vector (green) handles.
Free (black) handles.

To close the curve and turn it into a single continuous loop, select at least one of the control vertices on the curve and press C. This will connect the last point in the curve with the first one (The finished outline.). You may need to manipulate additional handles to get the shape you want.

The finished outline.

Leaving EditMode with ⇆ Tab and entering shaded mode with Z should reveal that the curve renders as a solid shape (Shaded logo.). We want to cut some holes into this shape to represent the eyes and wing details of the dragon.

Surfaces and Holes
When working with curves, Blender automatically detects holes in the surface and handles them accordingly to the following rules. A closed curve is always considered the boundary of a surface and hence rendered as a flat surface. If a closed curve is completely included within another one, the inner one is subtracted from the outer one, effectively defining a hole.

Shaded logo.

Return to wireframe mode with Z and enter EditMode again with ⇆ Tab. While still in EditMode, add a circle curve with Space >> Curve >> Bezier Circle (Adding a circle.). Scale the circle down to an appropriate size with S and move it with G.

Adding a circle.

Shape the circle using the techniques we have learned (Defining the eye.). Remember to add vertices to the circle with W >> Subdivide.

Defining the eye.

Create a wing cutout by adding a Bézier circle, converting all of the points to sharp corners, and then adjusting as necessary. You can duplicate this outline to save time when creating the second wing cutout. To do so, make sure no points are selected, then move the cursor over one of the vertices in the first wing cutout and select all linked points with L (Defining the wings.). Duplicate the selection with ⇧ ShiftD and move the new points into position.

Defining the wings.

To add more geometry that is not connected to the main body (placing an orb in the dragon's curved tail for example), use the ⇧ ShiftA menu to add more curves as shown in Orb placement within the tail..

Orb placement within the tail.

Now that we have the curve, we need to set its thickness and beveling options. With the curve selected, go to the EditButtons (F9) and locate the Curves and Surface panel. The Ext1 parameter sets the thickness of the extrusion while Ext2 sets the size of the bevel. BevResol sets how sharp or curved the bevel will be.

Bevel settings shows the settings used to extrude this curve.

Bevel settings
From Curves to Meshes
To perform more complex modelling operations, convert the curve to a mesh with AltC >> Mesh. Note that this is a one-way operation: you cannot convert a mesh back into a curve.

When your logo model is complete, you can add materials and lights and make a nice rendering (Final rendering.).

Final rendering.