Eibriel

First at all, the software in the title has a per usage order
I’ll skip the tracking related part of the tutorial (maybe can be on another post) cause I want to show a working VFX open source pipeline.

First at all, the ingredients:
Blender: Open Source Modelling and Animating software.
RIBMosaic: Open Source Blender2Renderman IDE.
Pixie: Open Source photorealistic renderer.
Ramen: Open Source Compositor

All are available on Linux, MacOSX & Windows (Ramen soon Now, Ramen for Windows too). Ramen only for Linux 64bits.

And Finally, a video:

Background

We track the video with our favourite tracker, (at date, not open source available ) and import the track information into Blender 2.49:

Blender-Tracking

Now we can make the model, shade and animate the Ufo as usual, the Map must be .tif in order to allow Pixie to open it.

Ufo model

All are ready to render!, we go to Render – > RIBMOSAIC Renderman (R) System, and a series of panels open. On Mosaic Settings flap we set the Export Directory where RIBMosaic will generate the textures, shaders, ribs, etc… On render presets select Pixie and (whit the cursor over the RIBMosaic window) press R. Pixie is launched and show us this:

Render

Pixie is really really fast, and generate very smooth render, but already have some bugs, and Reflection, Refraction (and SSS on 64bits) don’t work properly with RIBMosaic (you must create the shaders by hand, may be another Tutorial). Notice than Blender freezes since Pixie framebuffer is open, and come back when closes.

Well, now we can setup the motion blur, selecting the Ufo’s body and checking Transform MBlur on Geometry flap, doing the same to the cockpit and camera, and checking Export Animation to say RIMosaic to reexport on each frame.

When all are ready is time to render!, my animation have exactly 1079 rames, a lot! All must be setting properly.

First, we will generate the ribs and a render script with RIBMosaic to render from command line ( less intermediate process, more stability ). Check “Batch Scripts” on Mosaic Actions.

Now, remember the Blender freeze? well, on batch happens the same, and each frame showed halt the following. We must say RIBMosaic (to say Pixie) don’t show it. On Scenes Setup->Display Setup uncheck “Use” on framebuffer Display (usually the first one).

All are ready!!, On Mosaic Actions we press “Purge project export folder for ALL files” to ensure a clean export, press R and RIBMosaic process each frame patiently.

On ExportDirectory/Mosaic wee will find a file called STARTRENDER.SH, we hive it execution permissions and, well, obviously execute it (on a Termial!).

After… I don’t know, 12 hours of render is ready to composite!!

The right way: we need to open the background and the Ufo image sequences on Blender and export it to OpenEXR to avoid HDR related issues. (Pixie can export directly to .exr, but I don’t try it)

On our friend Ramen we go to Create->Input-Image.. and select any frame of background exr sequence. Press Ok and a new node will apear, we do the same with the Ufo sequence. Doubleclicking on a node, we can see the image on the Viewer.

Now we will Mix the images, we create a Layer node going to Create->Layer->Layer and connect the Yellow output of Background node to the Green input of the Layer node, and the Yellow output of Foreground node to the Red input on Layer node. Double click on Layer and Voila! is an Ufo over the De la Plata river!! (Is not the sea is the most wide river on the world ).

Ramen - Ufo

As a river have a brownly color, let us add a bit of color correction. Go to Create->Color->Color Correct and connect the Background output to the Correct red input, and the Correct output to the Green layer input. Deactivate the Autokey option to prevent color animation. Now you can play with the correction values!

Remember:

• Ramen is an HDR compositor, the ranges don’t are 0-255, but 0-1 (and <0 >1 as well )
• The first input field is for Red channel, then Green and finale one to Blue.

We can do the same to Ufo sequence, to integrate on the image. Remember that the color correction is splinted in: Master, Shadow, Midtone and Highlight to fine tuning. I recommend to put a complementary color on Highlight; for example, blue to midtones and red/orange to highlingh.

Well, now all see pretty good .

But we can do a last tiny thing. You see the sky on this image? It’s white, I was shooted the sequence with a photographic camera (I’m sorry, I’m poor ). A background so flashing must affect the Ufo, like the leaves of the tree.

Flash no corrected

We need to blur the alpha channel, but the blur must stay inside the Ufo. On Ramen (of course) we can work on alpha channel separately, then, we create a Copy Channel node [Create->Channel->Copy Channels] and connect both red inputs to Ufo color correction node output, and set on Copy Channels node properties (double click) Src2 Alpha on all the channels. Now, we will add a blur node [Create->Filter->Gaussian Blur], and connect the Copy Channel output to the Gaussian input, we can set blur amount on 2 for instance. Now we need to mix the original Ufo alpha channel with the Blurred one. To do that we can Duplicate our Layer node, selecting it and pressing Ctrl+D, now connecting, you can guess, the Copy Chanell output on Green input and Gaussian output on red input.

In any moment you can double click on a node to see the results, and if you like to see one node in the viewer but see the properties of another node you can Ctrl+Double click on the node you want to see and select on the viewer Context instead of Active (next to U button)

Blur Layout

Finally, we need to configure the Layer options, on Layer Mode set Mult, you will see a blurred alpha, with the blur staying inside the Ufo. Well, as final step we need to apply the new alpha to the Ufo, to do that we need a Set Matte node [Create->Channel->Set Matte], on Red input we connect the Correct output and on Blue input the Layer (recently created) output. And now finally replace the red input on our old Layer node from Correct output to Set Matte output.

Flash Corrected

We can control the blurriness animating the Layer2 opacity.

To render on Ramen we need to add a Output node [Create->Output->Image] connect it with Layer1 node and set the output file.

The file name must containg the %d string o say Ramen where add the frame number. Example: Ufo_%d.png

Going to Composition->”Render composition” we can set the range, quality and launch the render.

Pay attention to memory, cause Ramen uses to render a percent of the WHOLE memory, don’t a percent of the FREE memory. You can set the amount on Composition->Composition settings

The final work:

Remaining work:

• Shadows
• Reflections
• Particles
• Masking

But that I leave to you

I hope you have enjoyed this tutorial about VFX and geography , sorry about grammatical errors, I hope this has not scared you (I’ve fixed a few).

Regards,
Eibriel

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