Tag Archives: Blender

How to combine an Image Sequence into a video file with Blender

Did you know that Blender has a built-in video editor? We can use that to turn an image sequence into a movie file. I’ve described how to do this Photoshop here, but I thought it would be fun to try the same thing in Blender.

Here’s how to do it: Continue reading How to combine an Image Sequence into a video file with Blender





How to display a movie on a plane in Blender (Blender Render)

To show an animated video clip on a plane inside our scene, we can texture our plane object accordingly. Here’s how to do it using the Blender Render. engine (this won’t work in Cycles).

  • select the plane object and create a new Material on it (in the Materials Tab on the Properties Palette)
  • under the Shading Tab, select shadeless
  • leave all the other settings alone here

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Head over to the Textures Tab next to the Materials Tab and create a new texture. Set it to Image or Movie and select your video. You can also pic a single image or an Image Sequence here.

Under Image you can select at which frame your movie should start. Hit Match Movie Length to choose all frames in your movie (because we can’t tell how long it is, but Blender needs to know).

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Peek at the Preview section to see our video show up. Never mind the repetition or distortion for now.

In our final render, the background will probably look a little washed out. To combat that, head over to the World Tab and set the Horizon Colour to black.





How to hook a track to a vertex in Blender

Hooking is a technique with which you can attach one vertex to follow another object. This can be useful if the outline of an object (such as a plane) needs to be distorted when it follows tracking markers.

Here’s how to do it:

  • select the the object you want to track (such as an empty that follows a track)
  • now SHIFT select the object that you want the previous object to follow
  • switch into Edit Mode (TAB) and select the vertex you’d like to follow
  • now select CTRL+H and choose Hook to Selected Object

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The selected vertices will move with the hooked object.





How to create a translucent shader in Blender (Cycles)

screen-shot-2016-11-21-at-14-24-08By default all our 3D objects are opaque, meaning light does not pass through them. Like a brick wall. But many objects in reality let some amount of light through, like a piece of paper or a glass of lemonade. This partial transparency is called translucency.

In the picture above, light passes through the leaf, partially illuminating the ground underneath it. We can setup such a shader in Blender like this:

  • in between the Diffuse and Material Output node, connect an Add Shader
  • create a Translucent Shader and connect its output to the second input of the Add Shader (top or bottom does not matter)
  • connect the Color Output of your texture to the Color Input of the Translucent Shader

Here’s what such a shader looks like:

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In the above image, I have combined this translucent setup with a transparency shader, so that the leaf can be “cutout” using the texture’s transparent background. Here’s what that looks like:

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How to create a Shadow Catcher in Blender (Cycles)

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Setting up a Shadow Catcher in Blender is a bit more tricky than in other applications, but nevertheless straightforward if you know what you’re doing. I certainly did not when I first tried it, but thanks to this short YouTube video by Nonsense Blender Tutorials, I was able to set this up.

Here’s how to do it:

Continue reading How to create a Shadow Catcher in Blender (Cycles)





Why I joined The Blender Cloud

Blender LogoYesterday, while I was receiving my 13th chemotherapy shot at the hospital infusion suite, I’ve spontaneously joined The Blender Cloud.

Full of pride I mentioned this on Twitter, and Ton Roosendaal asked me to sum up what got me on board in one tweet. That’s not an easy feat, considering what the Blender Cloud has to offer, and the more I thought about it, the more reasons sprang to mind.

Here’s why I did it (in slightly more than 160 characters).

Continue reading Why I joined The Blender Cloud





How to create a transparency shader in Blender (Cycles)

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Texture files can have a transparency value, and as such we’d like to use it on occasion with 3D objects. The above image is created using flat square leaves, onto which an image of a leaf is projected. Outside the leaf, the area on the PNG file is transparent.

Here’s how to create a Cycles Shader in Blender that will show only the leaf and not the surrounding area of the texture.

Continue reading How to create a transparency shader in Blender (Cycles)





How to make a texture repeat in Blender (Cycles)

Sometimes we need a seamless texture to repeat on an object without the help of Photoshop. That’s possible in Blender’s Node Editor, albeit not exactly intuitive.

We need to add both a Texture Coordinate node, as well as a Mapping node to our shader to make this happen.

Here’s how to do it:

  • setup your texture map as usual (Add – Texture – Image Texture) and plug it into the Diffuse Color Input
  • your texture does not repeat at this point
  • add a Mapping Node (Add – Vector) and plug its vector output into your texture’s vector input
  • in the Mapping Node, select Texture. The X and Y Scale value below one determines the repetition of your texture
  • however, your texture does not show up at this point
  • add a Texture Coordinate node (Add – Input) and connect its UV output to the Texture Coordinate node’s Vector input
  • now your texture shows up

Here’s what such a shader looks like:

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How to grow grass on a landscape in Blender

grass-cpu-3m55s

I have previously grown some grass on a terrain in Carrara, and thought I’d try the same in Blender. I didn’t know much about how to do this, but the approach is very similar in Blender.

Like with my Carrara approach, I’ve modelled a few grass stalks from a cylinder first. Those are then replicated over a larger terrain. Neither a replicator nor a terrain generator exists in Blender, so here’s how I did it. Continue reading How to grow grass on a landscape in Blender





How to flip or rotate a texture in Blender

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When you’re UV unwrapping in Blender, it can sometimes happen that a texture doesn’t show the way you had intended it to. Instead it may appear rotated or mirrored (flipped).

Take the above example of a simple frame with a picture in the middle. When I originally added the texture file after unwrapping, the crab was displayed upside down, like so:

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What had happened? The UV map looked OK, did I make a mistake? Did Blender make a mistake? Nah, neither was true. I used the Pack Islands feature though, and in that case Blender may rotate islands randomly to maximise the space of the UV Map. Blender only did what I asked him to do.

Fixing rotated textures

It’s very easy to fix rotations: select the faces in question (either in the 3D view or the UV view), then hover somewhere inside the UV view and use the standard rotation command: R X 180 (followed by return). This will rotate the selected faces by 180 degrees, turning them upside down.

Fixing mirrored textures

Blender may also flip or mirror textures when packing islands, in which case my picture could appear like this:

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We can fit this phenomenon with the scaling command: S X -1 (followed by return). This will scale our selected faces along the X axis and inverse-stretch them, thereby flipping the image.

Notice that the UV map as such does not change visually, nor should it: we want our texture to remain in the same place. Also, when issuing those commands, make sure you position your mouse inside the UV view, NOT the 3D view – otherwise you’ll change the actual geometry instead of the UV coordinates.