Monday, 16 June 2014

Designing layouts for Hirst Arts moulds using Google Sketchup

Having spent a few evenings casting walls and doors for some sci-fi themed rooms, it was really hard not to go crazy and buy up more Hirst Arts moulds. So hard, in fact, that we now have mould numbers #301, #303, #320, #321, as well as the industrial edging mould #325.

The dental plaster turned up (about 10kg of the stuff - we had no idea what volume this was - it turns out, it's quite a lot!) so we've been busy casting more doors, walls, furniture, pipes, tank barrels, and a whole heap of other bits and bobs for making up some board game terrain.



Dental plaster is a great medium for casting these little blocks. Because it sets much harder than plaster of paris, and is much more resistant to chipping and damage, we can make up the gloopy mix just a little thinner than PoP. Using the "wet water" trick (spraying the moulds with window cleaner before starting) this thinner mixture helps reduce air bubbles in the casts. We've not yet got to the point where every cast is perfect, but a lot of our blocks are "good enough".

Just like using regular plaster of paris, we found that the dental plaster sets much harder, and takes on a slightly whiter appearance after a few hours "baking" in the sunshine.

Note the third and fourth blocks (from the left) are fresh out of the mould, and are slightly discoloured compared to the other pieces, which have had a full day drying out in the sunshine.

Thankfully we've had some really nice weather here at Nerd Towers, so the front garden has been filled with tray upon tray of plaster shapes, during the daytime, while they dry out.


We've now got a few boxes full of little shaped and pieces, so it's time to start fitting them all together. The first idea was to simply dry fit the shapes and see what looked nice.


The trouble with this approach is that the blocks are still quite fragile, and without gluing them together, they easily get knocked about and could get damaged if they were to fall over or drop on top of each other. What we needed was some way of making a "virtual dry fit" on the computer.

Incredibly, someone has spent a lot of time making Google Sketchup models for most of the Hirst Art moulds - at least, they have for the moulds we have got here. And the latest version of Ketchup (currently GS2014) has the model warehouse and extensions manager built right into it. So after downloading and installing the free version, it took no time at all to type "Hirst xxx" (where xxx is the mould number we have) and download a whole heap of ready-made 3d models for test-fitting.

We even downloaded a few 3d models of moulds we don't have, to help with the layout. For example, mould #270 is one for making floor blocks, for your tabletop terrain. Since we're going to be placing our models directly onto our electronic board game surface, and don't want to introduce any extra distance between the sensors and the playing pieces, we're not using these blocks - but the 3d models are useful for helping get everything lined up nicely.


Maybe we're just not used to the tools in Sketchup, but getting things to line up using the (rather crude) rotate and translate (move) tools can be quite tricky. Luckily, there's a number of extensions available, which allow you to align objects in your 3d drawing. We just searched the extension manager for "align" and installed the first one that came up - it works well enough and is easy enough to use to enable us to create a 6x8 grid from the 1" blocks in just a few minutes.

Getting useable models from the pieces of blocks was a little more involved, but after about an hour of wrestling with the Sketchup interface, we had a few wall sections ready to copy-and-paste into a board game layout. Here's an example of how the pieces from mould #301 fit together to make wall sections.


All this means we should be able to make up virtual examples of the room sections and extra industrial terrain for our spaceship-based game, without losing, breaking or damaging any of our recently cast pieces. The idea being, of course, that once we've dry-fit the pieces to make our board game sections, and got familiar with which pieces go where, actually constructing the real things should be that little bit easier!