OpenLLM-France/wikimedia huggingface dataset:
# Blender 3D: Noob to Pro/Creating a Light Probe

| previous module: "HDRi" | • Table of Contents • Glossary | next module: "Making Landscapes with heightmaps" |
The light probe is, in the simplest terms, a photograph of your environment. they work in very much the same way that reflection maps do, and are made the same way.
Equipment:
* A pure silver ball. Try a plastic Christmas tree ball ornament.
* A camera, preferably digital. If you have a high-end digital camera, you'll have less work ahead.
* A place you'd like to capture the lighting from. Try laying different things in your environment to get a good idea.
* Something to fire the shutter without touching the camera. For digital cameras, Paul Debevec recommends using a program that will take all the pictures for you.
* A tripod.
Set it up like so. Remember that the height of your camera and the height of the ball relative to each other controls the angle at which the horizon will be shot. In other words, shoot the ball at the same angle that you plan to shoot your 3D scene in. If your scene is animated... consider making a similar rig except attaching your reflective ball to a video camera as was done for Flight of the Navigator.
(note from a VFX pro who is using this technique for years: on a mirror ball everything is reflected except the area right behind the sphere opposite to the camera - where the tape is on the above picture)
The process:
* Set up your rig and take a series of images with varying exposure times.
* Taking 2 sets of pictures, each offset by 90 degrees, will enable you to get better coverage of the background and eliminate the reflection of the camera taking the picture.
| previous module: "HDRi" | • Table of Contents • Glossary | next module: "Making Landscapes with heightmaps" |
# Blender 3D: Noob to Pro/Creating animated GIFs using Blender and Gimp

| previous module: "Creating Ogg-Theora movies using Blender" | • Table of Contents • Glossary | next module: "3D Tiling Backgrounds For The Web" |
This tutorial will guide you through how to make a simple animated Gif Using Blender and Gimp. This is useful for creating Avatars for forums etc. This tutorial assumes basic knowledge of blender and Gimp, see the basic animation tutorial.
To start off you will need an animation, this usually should be no longer than 25 frames long.
* Open Blender. and delete the default cube and add a UV sphere, the default settings for the sphere work fine.
* Now set the camera size in the scene buttons (F10) to 50 by 50 (I am creating an avatar for deviant art where the required size is 50 by 50 pixels, you may change this if you want)
* set the frames to start at frame 1 and end at frame 20.
* select the sphere and insert a LOC keyframe at frame 1 and 21, then go to frame 11, move the sphere and insert another LOC keyframe. this will create a looping animation.
* Set the image type to PNG or JPEG (it doesn't matter) and render the animation.
Now to combine the images into an animated GIF using Gimp.
* Open the first image with gimp.
* Now click File-> open as Layer or press "Ctrl-Alt-O". Select the next frame and it will be added as a new layer. Repeat this for all of the images, or select all of the images by pressing "Ctrl-A".
* If you press Filters->Animation->Playback it should play the animation. It will probably have a low frame rate making it "choppy". this will be fixed in the next step.
* Change the frame rate to 40 ms(25 frames per second). Choose file->Export as-> "Name".gif, then choose Save as Animation.
Note: Don't know wheter this is an additional feature of Gimp 2.6.8 or not, but i found out following: In Gimp 2.6.8, within the export wizard, you have to choose option: -save as animation- first and next at the option: -single picture where not mentioned- the option: one single picture per layer. -Sorry i use the german version of gimp-
You should end up with something like this:
Alternatively, you may try using addons to create animated Gifs directly from Blender. 2 options include Spritify and Bligify
# Blender 3D: Noob to Pro/Curves In 3d

| Intro to Bézier Curves | • Table of Contents • Glossary | next module: "Deforming Meshes using the Curve Modifier" |

## Bézier Curves in 3d

In the previous page, we learned how to create and basically manipulate Bézier curves in two dimensions, as well as extruding them into the third. Here we will be exploring the '3D' button you may have been wondering about in the 'Curve and Surface' menu and some of its implications.
* Create a basic curve: Press 'SPACE - Add - Curve - Bezier' in case you have forgotten.
If you have been playing around with the control points on any curves so far, you will have noticed that they cannot be moved outside the flat plane made up by the X and Y axes. This is because it hasn't been enabled yet, so go ahead and enable it...
* Enabling 3D editing: Locate and press the button labelled '3D' in the 'Curve and Surface' menu.
Your curve should now look like this in Edit Mode:
Our previously simple curve has now been covered with arrows! These indicate the direction of the curve, and also the normal size and tilt. But more of that later...

## Getting started in 3D

Editing the curve should now be child's play, assuming you have already completed the tutorials on 3d meshes.
* Rotate the camera view: Use the MMB or some Numpad keys to rotate the view so you can see the 3d axes.
* Move a point: Select one of the control points (NB: A point, not a handle) and move it with GKEY. You may want to constrain its motion to the new Z axis using ZKEY twice.
If you rotate around the curve, you can see how the interpolation works in three dimensions, and that the arrows still follow its direction correctly. It is worth noting that they are all mostly vertically (for the moment at least), this will be discussed in the next section.

## Extruding revisited

I'm sure you will be delighted to learn that we can still use the Extrude option on 3d curves! Try cranking up the value, and you will see a surface created through your curve, at right angles to the 'normal' arrows.
The Bevel settings will also work as before, but you probably don't need to use them unless you are editing a 'filled' curve (CKEY).
Also, The Subdivided option(W, 1) still applies while working with curves. Just select two(or more) handles of the curve that are right next to each other, and subdivide. You should have a newly created handle(s) in between the handles you selected to subdivide.

### Bevel Objects

(Information on bevel objects to come...)

## Curve Tilting and Normal-scaling

Use TKEY to tilt the curve, clockwise or counterclockwise (looking along the line of the curve). For Blender version: 2.6x use Ctrl+T to tilt. Use Alt-SKEY to scale the curve, making it wider or narrower.

## Convert Curve to Mesh

Use Alt+C [ObjectMode>Menu>Object>Convert to>Mesh from...]. Shape typ 2D = mesh with auto add faces and edges Shape typ 3D = mesh only edges and vertex
(To be expanded...)
| Intro to Bézier Curves | • Table of Contents • Glossary | next module: "Deforming Meshes using the Curve Modifier" |
# Blender 3D: Noob to Pro/Creating Ogg-Theora movies using Blender

| previous module: "Illustrative Example: Model a Wine Glass" | • Table of Contents • Glossary | next module: "Creating animated GIFs using Blender and Gimp" |
Wikimedia Commons requires that movies be uploaded as Ogg-Theora (OGG) files. As of Blender 2.42a, this is not a builtin feature of Blender. To get OGG files from your finished animation isn't difficult, though. However, you'll need additional software.
There are basically two ways to generate OGG files: you can use one of the many fine video editors or you can use special conversion programs. Video editors like LiVES or Cinerella allow you to load your AVI or your rendered frames, manipulate them, and create the OGG file from it. Please refer to the editor's documentation on how to achieve this.
A disadvantage of a video editor is they are huge pieces of software, duplicating functionality that you already used when you created your animation file/s with blender. It's actually not necessary to install a video editor just for converting your animation to OGG Theora format.

## Converting saved frame picture files to Ogg Theora

It's actually possible to convert frame pictures that you saved before to OGG format movies. The ffmpeg2theora software package, which is available in source or binary for all relevant systems, is capable of batch-processing files into an Ogg format movie. For example, if your frames were saved as PNG (with filenames filename001.png, filename002.png, etc.), you could convert them to a soundless OGG file with:
Sound is possible too, as well as being able to set the quality and framerates. Consult the ffmpeg2theora documentation for more.

## Converting AVIs to Ogg Theora

ffmpeg2theora can also convert AVI movies to OGG. Usage example:
# Blender 3D: Noob to Pro/Curve and Path Modeling

| previous module: "Lighting Suzanne: Introductory one lamp lighting" | • Table of Contents • Glossary | Intro to Bézier Curves |

## Why Use Curves?

You’ve learned how versatile mesh objects can be, and how they can easily produce flat surfaces with sharp edges and even give a convincing representation of curved surfaces with rounder edges. So why do we need a separate kind of curve object at all?
There are important reasons.
* The various kinds of curves and surfaces/patches (Bézier, NURBS etc) were used in computer graphics before meshes were developed. In the days when memory was more expensive, they offered a more compact way to represent complex shapes. Even now, they are still common in CAD and other technically-oriented graphics applications, where they make it easy to precisely specify the shape of a curve. Thus, if you are importing data from such applications, you will need the ability to represent such curves—even if you end up converting them to meshes before applying materials and textures for rendering.
* You can use curves as guides for shaping meshes. This makes it easier to construct certain kinds of complicated curved shapes. Particularly since it is simpler to make changes to the curve (with fewer control points), than after it has been converted to a mesh. To this end, Blender defines scaling radius and tilt angle settings for curve control points, which make no difference to the appearance of the curve itself, but have an effect when it is used to deform another shape.

## Bézier Versus NURBS

In the following pages, you will come across two kinds of curves/patches.
Bézier objects only occur in Blender as curves, while NURBS (“Non-Uniform Rational B-Spline) objects can be curves or surfaces. If you’ve used 2D drawing programs like Inkscape or Adobe Illustrator, you would have come across Bézier curves before. NURBS curves are a mathematical generalization of these, which are heavily used in CAD applications. Unlike Bézier curves, NURBS curves allow the specification of a variable weight for each control point, which governs how closely the curve passes to that point.

## More Than You Wanted To Know About Curves

As usual, Wikipedia has the lowdown on all the interesting trivia about
* Bézier curves
* NURBS curves
| previous module: "Lighting Suzanne: Introductory one lamp lighting" | • Table of Contents • Glossary | Intro to Bézier Curves |