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FoxFire Compositing Tutorial


FoxFireWe wrote earlier about Firefox Flicks Blender Animations. During the creation of the FoxFire entry the author has written a really good tutorial on using Blender's Sequencer and the Alpha Over effect in particular. This is a great effect and an even greater mystery to many, but this tutorial will help you understand just how to setup one of the most popular sequencing effects!

Read the Tutorial

One minor problem that this author brings up is Blender's line drawing capabilities. He says:

"In my case, I had to do this to overcome a limitation in Blender's edge drawing (I wanted the snow in the scene to be drawn without edge rendering) while keeping shadow interaction between different pieces."

This isn't actually correct - it isn't a limitation it's a perk! Now, it can be a limitation if you don't want to use the simple fix. See, Blender uses the unified renderer to draw the lines onto the edges of the meshes. This produces that great hand drawn cartoon look. The problem is that Blender doesn't draw edges on every kind of material. It specifically excludes alpha materials. This is the perk/simple fix to rendering one set of images without having to composite them. Simply, just take the snow (in the case of this tutorial) mesh and give it an alpha of .999 - this isn't quite opaque of 1.0 but no one could tell! Remember not to enable Ztransp or RayTransp and it will still be opaque to the renderer. This draws lines on everything but the snow!

Now, this isn't without it's own set of limitations and that comes to play when you want to have lines on transparent objects such as glass or icecubes or anything transparent like. If that be the case then you need to enable the All button in the Edge Settings. This will treat all materials, even transparent ones, as edges to be rendered on. In that case the above tutorial will suit you just fine! :D

About the Author

Daniel LaBarge

Blender Artist & Contributor at ID Studios [] Web Designer & Programmer at MonsterWeb []


  1. Hi everyone,

    I don't know if you noticed, but this post was written by a new member of the BlenderNation crew: Daniel laBarge (Prince). Daniel, welcome to the team!


  2. Just to note on the tutorial. I noticed the author had the "fox" character on both the foreground and background. When I made a similar animation (it even had snow, too!), I was able to do much the same thing but with faster render times by separating the character, shadow, and background rendering, assuming the background is static. Just a single rendered image for the background, and then lots of images from the foreground render with the background material transparent but still receiving shadows. Just a tip.

  3. Hey ho,

    Wow, two posts in two days. I'm flattered! ^_^

    On the way I did the renderings: I tried what you suggested and my shadows went wonky. I have *no* idea what was going on with the shadows, but no matter how many times I tried they would not behave without the character being *exactly* where he was. I moved him once, trying to reposition him for a better angle, and the shadows stretched to enormous lengths. (It's not the only bug I ran into during the project, but I only reported the ones I could consistantly reproduce. I had another where half of my character, in fully-shaded mode, would turn to white triangles. He rendered fine; it was only an issue in OpenGL with lights. Never figured out how to reproduce it or to fix it. Another was the fact that the proportional editing tool randomly breaks and can't be reset.) In the end I found a solution that worked and clung to it tenaciously.

    I think the file I published to the site no longer has that issue, so I might go back and try again. However, thinking about it I might wait for the next versions so separation of shadows is easier. One thing I'm looking forward to is being able to hold each character on their own renderlayer, so that line drawing can be even more configurable.

    As for the other suggestions with the unified renderer, well... I'm going back to test those out right this minute. ^_^

  4. As a fan of noodles (nodes), I'll just add that the same compositing can be done with nodes (complete with a nice intuitive UI). Thought I'd just draw some attention to nodes before I slip back into the inky shadows.

  5. for those who want a "real" tutorial about the sequencer check out bart's video sequencer tutorial its a part of the official documentation so i think that u will not think its hard to find
    anyway here it is.

  6. Personally I can't make the 0.999 Alpha thing work. It always renders edges (Blender 2.41), even with 0.000 Alpha!

    The alternative (which I often use) is to leave turn on ZTransp for the material with Alpha being whatever you want. No edges are then drawn for that material but it remains opaque, unified renderer or not.

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