Random Delete

Many of you are now getting into the evaluation part, and you might be finding that the analysis is quite slow sometimes. If you have 20,000 windows, and you try the analyse Sky View Factor, you will probably get the dreaded 'Memory Allocation' error...

So you need to reduce the number of surfaces. If you have a lot of surfaces, then you can actually just select a random sample to analyse. As long as the selection is random, the results will still be representative of all the surfaces. So in the case of 20,000 windows, you can analyse just 10% or 20%.

To help you do this, I have created a Random Delete node:

• http://files.patrick.janssen.name/2010/random_delete.zip

Scenic View Factor

While helping Ying Ying this morning, I created another evaluation node, called Scenic View Factor. This node will allow you to input a set of points that identify scenic views. The inputs are as follows:

• Input 1: The faces you want to analyze
• Input 2: The obstructions that might block your view
• Input 3: The scenic view points.

 The node will then work out the number of scenic points that you can see from each face that is analyzed, and display the result as a colour and a percentage. So 100% means that you can see all the scenic points from that face, will 0% means that you can see none of them.

• http://files.patrick.janssen.name/2010/scenic_view_factor.zip

Triangular grids

Some of you need grids that are triangulated with equilateral triangles. Here is an otl to do it:

• http://files.patrick.janssen.name/2010/tri_grid.zip

Bad designs are good

During tutorials yesterday, we had a number of discussions about the importance of keeping your low performance designs.

You need to present all your variants, even if they are very low performance. You will have created developmental and evaluation processes. You will of course be hoping that the developmental process produces design variants which, when evaluated, have good or at least reasonable performance. But in the end, this may not be the case.... the performance may be terrible! But this does not matter - do not try and hide these designs. We are interested in the success of the process, not the success of the designs. And a process that highlights that your designs are weak is a good process... You can then try and change your developmental process to produce  better designs.

Crit next monday

This is a reminder that as stated in the schedule, we will have a crit next Monday. For this crit, the most important thing is to have a Pareto graph... we want to see a set of variants evaluated according to some criteria and plotted onto the Pareto graph for comparison.

Other things that you should also have are:

• developmental diagrams
• evaluation diagrams
• a map of your design process which shows what you have been doing in the last few weeks

ps I have recovered from the flu, so tutorials as usual today

Passive Zone Proportion (updated)

I have updated the Passive Zone Proportion node so that it now works much faster. Instead of 'brickering' polygons, I now use an offset, which is a lot faster. The inputs are also a bit simpler - no need to input the walls any more. Just the floor polygons will do. The node is in the same place as before:

• http://files.patrick.janssen.name/2010/pzp.zip

For those who still want access to the old node, it is here:

• http://files.patrick.janssen.name/2010/pzp_old.zip

Evaluation nodes

In order to help people started with their evaluation processes, I have been creating various evaluation nodes that that I have been uploading on the blog. So far, I have created the following nodes:

• Unobstructed Vision Area node for evaluating horizontal views 
• Passive Zone Proportion node for evaluating % passive floor area. This relates daylight levels inside the space.
• Sky View Factor node for evaluating % visible sky. This relates to levels of daylight and views (feeling of enclosure).
• Sun View Factor node for evaluating % of visible sun. This relates to solar radiation.

There are various other things that can be measured. I may add a few more nodes. There are also more advanced simulations using EnergyPlus and Radiance, but it is better to start with the simpler types of evaluations.

They key for you is to start thinking about how you might use such nodes in you evaluation. Also, try and figure out the process at a small scale - then, once you know what you are doing, scale it up. These evaluations can be slow, so don't just put thousands of polygons into one of these nodes and then wonder why it does not work. You will probably not be able to evaluate the whole 1 km2 in one go - you will need to break it down.

A number of people have asked about how to insert these evaluation nodes and the otl files. When I create a node, I typically create one or more otl files, and one hipnc file. The otl files contain the actual node, and the hipnc file is just an example of using the node. If you want to use one of these nodes in you file, you need to install the otls. First copy the otl's to the folder where you are working, and then in Houdini menu go to File > Install Digital Asset Library