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[edit] Wat is Grease Pencil (Vetkrijt)?

Deze pagina is gebaseerd op de grease pencil release logs voor Blender 2.48

De mogelijkheid om in vensters te tekenen gebruikmakend van vrije bewegingen om te schetsen en aantekeningen te maken heeft veel voordelen voor samenwerking en planning. Dit kan worden gekoppelde aan traditionele 2D werkprocessen met potlood en papier, waarin ruwe richtinggevende schetsen vaak gebruikt worden voor planningsdoeleinden of om een idee snel over te kunnen brengen. Het is maak nuttiger om aantekeningen direct te kunnen aanbrengen op het werkstuk, dan om dat te doen in een afzonderlijke plek (zoals een ander deel van het venter of een totaal andere applicatie).

De naam "Grease Pencil" (Vetkrijt) is afgeleid van de ouderwetse wasco's en het vetkrijt dat vroeg CG tekenaars gebruikten om bogen en andere planningsnotities op hun beeldscherm te markeren.

Buiten dat het "Grease Pencil" (Vetkrijt) kan worden gebruikt om houdingen en bewegingslijnen te tekenen is er nog een aantal scenario's te bedenken waarin het nuttig kan zijn, waaronder:

• Planningsoverzicht en opzetten van modellen;
• Hulpmiddel waarmee een regisseur scènes kan beoordelen;
• Whiteboard en aantekenhulpmiddel voor onderwijzers.

[edit] Beginnen met Tekenen

1. De eerste dat komt kijken bij het gebruik van het "Grease Pencil" (Vetkrijt) is het aanzetten ervan in het venster waarin het gebruikt moet worden. Dit kan door de "Grease Pencil" (Vetkrijt)-optie te keizen uit het View menu; klik op het "Use Grease Pencil" (Gebruik Vetkrijt) vinkje dat verschijnt.
2. Kies vervolgend "Add New Layer" (Voeg nieuwe laag toe) om een nieuwe tekenlaag toe te voegen. Als er met een nieuwe tekening begonnen wordt is dit niet nodig (omdat een nieuwe laag dan automatisch wordt aangemaakt), tenzij lijndikte, -kleur en -transparantie moet worden aangepast. Als er echter al andere lagen aanwezig zijn, is het noodzakelijk om op de knop te drukken.

Het "Grease Pencil" (Vetkrijt) is beschikbaar voor de volgende "Window Types" (Venstertypes): 3D Venster, Nodes Editor, Image Editor en Sequence Editor.

Let op: "Grease Pencil" (Vetkrijt) gegevens zijn op dit moment uniek voor het specifieke schermdeel waarop ze aangemaakt worden, hetgeen betekent dat als een View wordt verwijderd, al deze gegevens verloren gaan.

Het lege 'Grease Pencil' Menu.

Nu zijn alle opties zichtbaar.

[edit] Tekenen

[edit] Snel gebruik (voor een paar lijntjes)

• Een lijn tekenen: Terwijl je Shift LMB ingedrukt houdt, beweeg je met de muis om een nieuw schetslijn te tekenen. Als je de muisknop loslaat, eindigt je schetslijn.
• Lijn(en) verwijderen: Met Alt RMB ingedrukt kun je met de muis schetslijnen wissen die in de diameter van de 'gum' vallen.

[edit] Makkelijker werken (voor meer complexe schetsen)

1. Ze het "Draw Mode" (Tekenmodus) vinkje aan in de rechterbovenhoek van het "Grease Pencil" (Vetkrijt) paneel.
2. Gebruik tijdens het tekenen dezelfde muisknoppen als bij het snel schetsen, maar zonder de extra toetsen:  LMB om te tekenen,  RMB om te wissen.

[edit] Special Tricks in 'Draw Mode'

• Drawing a straight line: Hold CtrlKey while dragging with the LMB to draw a straight line. Although a wavy line will still appear on screen, only the endpoints of that stroke will be used for the final stroke that gets stored. This is a useful feature for architectural uses.
• Drawing a dot: Simply click on a spot. This is mentioned here because it is not available when 'Draw Mode' is not enabled.

[edit] For Tablet Users

• The thickness of a stroke at a particular point is affected by the pressure used when drawing that part of the stroke
• The 'eraser' end of the stylus can be used to erase strokes too

[edit] Sensitivity When Drawing

The default settings for the sensitivity to mouse/stylus movement when drawing, have been set so that there shouldn't be too much jitter while still allowing for fine details to be made. However, sometimes these settings may not be appropriate, in which case, the defaults can be found in the User Preferences under Edit Methods.

• Manhatten Distance: The minimum number of pixels the mouse should have moved either horizontally or vertically before the movement is recorded. Decreasing this should work better for curvy lines
• Euclidean Distance: The minimum distance that mouse should have travelled before movement is recorded. Imagine this as length of imaginary string between last recorded position and mouse-cursor.
• Eraser Radius: This is self-explanatory. It is simply the size of the eraser 'brush', so changing this will affect how likely strokes are going to be covered within the eraser brush and thus erased
• Smooth Stroke: This turns the post-processing step of smoothing the stroke to remove jitter. It is only relevant when not drawing straight lines. By default this is off, as it can often cause 'shrinking' of drawings, which is sometimes not that desirable.

[edit] Additional notes

• When 'Draw Mode' is enabled, many of the other events that are attached to the LMB and RMB are blocked.
• If 'Swap mouse buttons' is enabled, this has no effect on the mapping of mouse-buttons to drawing/erasing operations. However, it may become difficult to select using Shift-LMB in such a situation, in which case the tiny 'Lock' icon beside the 'Draw Mode' button should be enabled to help alleviate the problems (that will simply disable drawing from occurring with Shift-LMB).

[edit] Drawing Planes

Sketches are only relevant for the view/view-angle (referred to here as the 'drawing plane') that they were drawn at. There are several different options for how individual strokes (determined by the settings in use when the stroke was created) will be displayed.

• Screen-Aligned: This is the default drawing plane for the 3D-View, and is also the viewing plane that gets used for the other editors when 'Stick to View' is disabled. All new strokes that get drawn in this mode appear to be 'stuck' to the screen-surface (much like markers on a monitor), and will therefore stay unaffected by zooming/translating/rotating the view
• View aligned (default for all 2D Views): New strokes are affected by manipulating the view. This can be turned on/off using 'Stick to View' option.
• Drawing in 3D-Space (only available in the 3D-View): New strokes are drawn in 3D-space, with the position of their points being determined by the position of the 3D-cursor and the view rotation at the time.

[edit] Layers

Grease Pencil sketches are organised in layers, much like those you could find in the GIMP or Photoshop. These layers are not related to any of the other layer systems in Blender, and also do not have an upper limit on the maximum number of layers that can be used. Like the layers in the aforementioned apps, these layers can also be renamed, locked, hidden, and deleted.

Their main purpose is to collect together a bunch of sketches that belong together in some meaningful way (i.e. "blocking notes", "director's comments on blocking", or "guidelines"). For this reason, all the strokes on a layer (not just those made after a particular change) are affected by that layer's colour, opacity, and stroke thickness settings.

By default, most operations occur only on the 'active' layer. The active layer can be identified as the one with the different panel colour (in the default set, an light orangy-brown colour). Clicking on a layer, or changing any of its settings will make it the new active layer.

The active layer can also be identified by looking at the status indicator (in the top right-hand corner of every view with Grease Pencil data being shown). Animated Sketches

Grease Pencil can be used to do basic pencil tests (i.e. 2D animation in flipbook style). Sketches are stored on the frame that they were drawn on, as a separate drawing (only on the layer that they exist on). Each drawing is visible until the next drawing for that layer is encountered. The only exception to this is the first drawing for a layer, which will also be visible before the frame it was drawn on.

Therefore, it is simple to make a pencil-test/series of animated sketches:

1. Go to first relevant frame. Draw.
2. Jump to next relevant frame. Draw some more.
3. Keep repeating process, and drawing until satisfied. Voila! Animated sketches.

[edit] Onion Skinning

Onion-skinning (also known as ghosting), is a useful tool for animators, as neighboring frame(s) are lightly drawn by Blender. It allows animators to make judgments about movements, by comparing movement from different frames.

Usage Notes:

• Onion-skinning is enabled per layer by clicking on the 'Onion Skinning' button.
• The 'GStep' field controls how many frames will be drawn. When 'GStep' is 0, only the drawing on either side of the current frame will be visible. Otherwise, it this field specifies the maximum number of frames on either side of the current frame that will result in a neighboring drawing being included.

[edit] Adjusting Timing of Sketches

It is possible to set a Grease-Pencil block to be loaded up in the Action Editor for editing of the timings of the drawings. This is especially useful for animators blocking out shots, where the ability to re-time blocking poses is one of the main purposes of the whole exercise.

1. In an Action Editor window, change the mode selector (found beside the menus) to 'Grease Pencil' (by default, it should be set to 'Action Editor').
2. At this point, the Action Editor should now display a few 'channels' with some 'keyframes' on them. These 'channels' are the layers, and the 'keyframes' are the frames that each layer has. They can be manipulated like any other data in the Action Editor can be.

All the available Grease-Pencil blocks for the current screen layout will be shown. The Area/Grease-Pencil datablocks are drawn as green channels, and are named with relevant info from the views. They are also labelled with the Area index (which is currently not shown anywhere else though).

[edit] Copying Sketches

It is possible to copy sketches from a layer/layers to other layers in the Action Editor using the Copy/Paste buttons in the header. This works in a similar way as the copy/paste tools for keyframes in the Action Editor.

Sketches can also be copied from one screen (or view) to another using these tools. It is important to keep in mind that keyframes will only be pasted into selected layers, so layers will need to be created for the destination areas too.

[edit] Converting Sketches to Other Forms

In the 3D-view, sketches on the active layer can be converted to geometry, based on the current view settings. Sketches are converted into geometry by transforming the points recorded when drawing (which make up the strokes) into 3D-space (based on the current view settings). Currently, all points will be used, so it may be necessary to simplify or subdivide parts of the created geometry for standard use.

Sketches can currently be converted into one of three types:

• Armature: Each stroke is converted into a bone chain, which is assigned to an armature named after the active layer. The bones in each chain are connected and parented to each other. Also, bones inherit their envelope radii from the thickness of their stroke at each recorded point.
• Bezier Curve and Path: Each stroke is converted into a separate curve within a curve object that's named after the active layer. Handles are automatically set to be 'free' handles (i.e. the black type), and are set to be in the same places as the control-points. The weight/radius of the curve at each control-point is set to equal the thickness of the stroke at each recorded point. However, in order to see that, you need to set the 'BevOb' field to use a CurveCircle or similar curve.

Redirects to fix

• Manual/Interaction in 3D → Doc:Manual/3D Interaction
• Manual/LocalGlobal → Doc:Manual/3D interaction/Navigating/Global View or Local View
• Manual/Manipulation in 3D Space → Doc:Manual/3D interaction/Manipulation