I was inspired by a kinetic sculpture built by Pleuni Bongers, Bas Boon, and Kees Hoeijmakers. Their works can be found at www.basgoed.nl

At first I had a difficult time understanding how the pieces moved as one, so I made a maquette out of paper. I followed the original artist’s pattern of having right triangles with different lengths for their opposite and adjacent edges, so that there was a 5-pointed star pattern. Ultimately for my Houdini animation, however, I made right triangles where the opposite and adjacent sides were equal, resulting in a 4-pointed shape.

 

Process pictures and further description below.

I started by following the blueprints I had drawn for myself, so that I would only have to make a portion of the sculpture before copying it and rotating it. I used add nodes to make points to create the triangles, and those that would move have expressions using sin based on the frame number. For some of the movements, I used 1*abs or -1*abs to clamp the value in the function, and stop the geometry from clipping through itself when it passed 0 in whichever direction it was traveling.

 

Once I had finished the partial of the sculpture, I transformed it 180 degrees so that the point where the triangles met would face inwards when it was copied. I did not use a copy node and instead used object merges and transforms to create the combined sculpture. I did this because I wanted more control over the placement of the individual pieces. I copied the final sculpture twice and rotated it 45 degrees, so that there were 3 sculptures for compositional reasons.

 

After the movement was complete, I went back to the triangles in the smaller portion and polysplit them and grouped faces for material assignment. For the inner glowing triangles, I first tried an opacity map and had a point light behind each sculpture, but it was not creating the desired effect. I then began playing with emission and found, when I applied the map I had been using for opacity, it gave me the desired effect.

 

Following critique, I increased the reflectivity of the white triangles so they didn’t have a papery feel, and altered one of my camera angles to be less dead-on. I also made slight lighting changes to fix a strange shadow forming between two of the sculptures.