Blender rendering

Blender rendering

Offline path-traced frames and animations using Blender’s BVtkNodes workflow. VTK sequences should use zero-padded indices (e.g. case_000.vtk … case_999.vtk) when driving time-dependent imports—see hints at the end of this page.

Install Blender and add-ons

• Install Blender.

• Install VTK inside the blender python environment.

  Hint: to add vtk support in blender, please visit https://github.com/simboden/BVtkNodes/blob/master/build_vtk.md.

• Install BVtkNodes add-on, which can be obtained from https://github.com/tkeskita/BVtkNodes. Thanks Silvano Imboden (s.imboden@cineca.it), Lorenzo Celli, and Paul Mc Manus for the original work, and Tuomo Keskitalo for functionality extending and maintaining.

  Hint: to install add-on in blender: go to Edit → Preferences → add-on, and install the add-on by selecting the zip file downloaded from the github main/master branch.

Rendering

• Switch to the BVTK Node Tree editor, and create a new node tree similar to the following figure.

blender_enditor_layout

node_example

• Switch back to the 3D Viewport editor, and you should get a scene as following.

render_example

• Play with the VTK filters and blender feature to polish the scene (color represents the stress). Below is an animation of membrane pulling and twisting, where the result data is simulated and created in Phynexis.

Hints:

• Shortkeys: ctrl+alt+NumPad 0 to set the camera to current view; G to translate the selected object; x to delete the selected object; ctrl or shift + mouse operations to pan, zoom-in and zoom-out the view.

• Rendering settings: suggest to use cycles engine, with the Max Samples set to 10.

• For rendering animation: the Time Selector filter will change the file name according to the index of frame. At current stage, the file names should be indexed with sequential numbers, i.e., xx_000.vtk, xx_001.vtk, xx_999.vtk, etc. One can play with the vtk filters for possible extension.