Blender is a remarkable 3D modelling and animation program. There is one minor issue with it, though: it isn’t easy to use multiple computers on a network to render in parallel. That’s exactly what this program will do. It connects to multiple computers on your network, and lets Blender render in parallel on each. This will drastically improve your rendering speeds!
Multiblend is a standalone Python script that runs from outside Blender. This means you can even use it on machines that don’t have powerful graphics cards, like older computers or servers.
For the exact changes between releases, please read the changelog.
Download Multiblend 1.3
To give you a feeling of how Multiblend works, here is an overview of its usage.
Read on for the details!
The configuration is read from
Having just one of the two is fine, but you can also have both if you want. An
example says more than words:
[main] chunks=100 nodes=2 projectpath=/home/sybren/blender ssh=/usr/bin/ssh -Tq scp=/usr/bin/scp -q [node0] hostname=localhost blender=/opt/blender-2.41/blender workdir=/home/sybren/tmp [node1] hostname=zebra blender=/opt/blender-2.41/blender workdir=/tmp
Lines 1-6 describe the main section. Line 2 “chunks” contains the number of frames that make up a chunk. A single computer will get this number of frames in one run. Line 3 “nodes” contains the total number of computers you want to use to render. Line 4 “projectpath” contains the local path of your Blender project. Lines 5 and 6 “ssh” and “scp” are set to your SSH and SCP client. You probably don’t need to change them.
Lines 8-11 describe node0, the first computer to use. Line 9 “hostname” reflects the hostname or IP address of the computer on your network. In this case, it’s a special one - because it says “LOCAL” Multiblend won’t connect to it using SSH but simply run Blender locally. Line 10 “blender” points to where Blender is installed on this computer. The last line “workdir” tells Multiblend where the temporary files can be stored on the node.
The last lines, 13-16, describe another computer. You can add as many of them as you want, numbering them node2, node3, etc.
Let’s assume that your installation is the same as mine (tough chance, but I have to pick something as an example) and your Blender file resides in /home/sybren/blender. Let’s render the first 1200 frames of the file called test.blend. This is how that’s done:
python multiblend.py -b test.blend -s 1 -e 1200
This will run Blender on all computers in the configuration file. It keeps running until the animation is rendered completely. If you want to stop prematurely, press Ctrl+C.
The first part - reaching your computers via SSH - is beyond the scope of this document. If you need help with this, just ask me for help. You do need to ensure that you can use SSH without passwords, though, since Multiblend doesn’t know your passwords. Read the manual pages for ‘ssh-keygen’ and ‘ssh-copy-id’ for that if you don’t know how to set it up.