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Combining CNC milling and 3D projection mapping for large format models
(e.g. walls or steep parts in the terrain).
The trick is actually simple. A camera in Blender 3D receives light from certain light sources that interact with the material of the virtual surface (our mesh) and captures this light, through a virtual lens, onto a virtual sensor. A virtual image is born. On the other hand, a projector works in the opposite direction. A physical emitter (the projector’s lamp) radiates a virtual image through a physical lens onto a physical surface. In our case, the virtual surface (our mesh) and the physical surFig. 4 –The setting of the model and the proface (our CNC- jector. Notice the angle of 45 degrees of the table on which the model is placed. milled model) are more or less the same. We only had to set up our virtual world identically to our physical world, which eventually succeeded! After a few hours of tinkering with rulers and protractors in the real world, and much more hours with Blender 3D in the virtual world, our first tests were promising. In fact the most difficult part was the vertical lens shift of this type of projector. Luckily, it is possible in Blender 3D to set up a vertical Fig. 5 –TCamera and model setting in Blender 3D.
BLENDERART - ISSUE 40 | NOV 2012
shift as well. THE PRELIMINARY RESULT
From an artists’ point of view, our materials, textures, light settings, etc. need considerable improvements. After all, this is a basic test.
The photos included in this article also reveal that the mapping is not 100 percent correct. We are fully aware of this, but we Fig. 6 –3D projection mapping, using a regular can attribute projector, a CNC milled model and Blender 3D. this to the fact that our measurement instruments were not designed for precision work. Also, our ‘test lab’ is located in an historic building, where floors and walls are not always squared, making it difficult to measure. Much work is being done at the moment to generate the complete mesh of 6 by 2.5 meters. We have also been working on the animation part, where different techniques were applied. We used keyframing on materials, textures and spot lights, and some modifiers (e.g. build) gave interesting results. However these results are difficult to show in this article. More tests are being done at the moment and further investigation is necessary, especially for a setting with multiple beamers. Nonetheless, we do hope that this description of our work in progress inspires other Blender artists with similar projects. ACKNOWLEDGEMENTS
The Ypres Salient research project is funded by the
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