TOPOMESH – Yann Houllard


Categories: Tutorials

Here, the idea was to create a sculture made from triangles, as a tribute to the topography of Prague and Petrin Hill. It’s an installation giving light and experience to the visitors. There is a video at the end of the tutorial showing its Virtual Reality.





Following, let’s find the tutorial of its parametric design.

As a blanket, the purpose is to have a square shape deformed by the topography of Prague. It will play with the light thanks to the circles in the middle.




First, let’s draw 21 curves on Rhino, with 10 cm between each one. And let’s add 21 points on each one (_PointsOn)





When you have the points, move them (unit Z) to obtain differents heights wich create the topography of the Petrin Hill.



Open Grasshopper. Set the curves to curve icon and create a network (Curve –> Divide Curves (21) –> Join everything with Delaunay Edges to create the network).




Unfortunately, there are some mistakes as we can see on the first plan, we have to control the network and erase the lines that we don’t want. (Delaunay –> Lenght –>Smaller Than 20.16  and Bounds –> Dispatch –> Final lines). 10 lines are not available. We erase them.




Then we would like to transform these lines in a system of pipes to obtain the final structure of the sculpture. (Lines –> Mesh Pipe with settings (Radius, accuracy and segments – it means “definition of the pipe” –> Mesh Join). We obtain a mesh of pipes.




Now we have the structure of the sculpture. The cylenders as accessories are missing. But, since the beginning, we are working with lines and now we would like to work with some surfaces. First we need to create it. (Weavervird’s mesh from lines –> Mesh explode –> Deconstruct mesh). We obtain points of the mesh.




To get the surface we will use the points of the mesh and create a closed polylines then, planar surfaces from them. (Deconstruct mesh –> Polylines –> boundary surfaces).

Now, we have to find the center of each triangle to put the cirle (following the shape of the strcuture). (Deconstruct mesh –> Average –> Surface Closest Point –> Evaluate Surface). It’s done.




Now, In the last part, we want to play with the size of the cylenders to give more or less intensity to the light according to the distance with the top of the Petrin Hill. (Average –> Vector 2 points – We create an attractor point on the top of the hill –> Multiplication –> Multiplication – for the variation of the size).




The final task is to create the cylenders. (Cylender with the lenght 0.25 –> Cap Holes to close the cylender). We connect them with the others settings (Evaluate Surface and Multiplication –> Cylenders).


We obtain the cylenders playing with the light, following the structure.



Here, there is the final script with all the steps.




Final shape.


SCRIPT  :   topomesh

I used the plugin Weaverbird, I would like to thank its autor Giulio Piacentino.



Trailer of the sculpture design and its Virtual Reality







Some words to explain how to create a virtual reality object.


First open the software Unreal Engine 4. Create a new project and choose the point of view.




Then,  in Content browser (bottom of the screen) import your file ( .obj file). Be carefull with your file (scale, unit, …).




Then you will be able to walk around your project. Of course you can change textures, add some lights easily. The best way is to use the virtual reality in this software but you can export it in .obj or .uproject if you want to share it.