< it does sound complicated!

Not really! ;)

Hi Sutts, it isn't good in general to have your models at a scale like that where the coordinate values are in the hundreds of thousands. The way floating point math works is that the precision of calculations is reduced when numeric values are far away from the origin like that.

One of the differences between 32-bit and 64-bit code is that floating point operations in 32-bit code using the x87 floating point instructions would actually have an extended 80 bit register value so some operations could be carried out at a higher precision before being stored back into memory. That has been lost in the transition to 64-bit, the 64-bit instruction set does not have that kind of extended precision.

So a side effect of that is that it is possible for cases that are difficult to calculate numerically like you have set up here that the 32-bit version could behave better than the 64-bit version.

However, what you're trying to do here is really not a great fit for NURBS in general. NURBS are not well suited for terrain, polygons are a better fit for this.

- Michael

That looks pretty impressive thanks. Will definitely look into that feature.

Thanks Michael, that makes perfect sense. Pure laziness on my part for not scaling those values back. I'll fix that and try projecting again.
The end goal of this particular exercise is not the terrain itself. I'm modelling an airfield layout with MOI and need the terrain to project the 2D model onto so that the model follows the terrain when I place it on the landscape in the Unreal 4 engine. I'd much prefer to work with MOI but if I can't get it to handle these massive chunks of data, can you suggest an affordable polygon modeler that might handle it please?

I'll continue to use MOI for everything else as it's absolutely superb. You must have put a lot of time and thought into the interface as it's amazingly intuitive. The projected snap points are so useful and all the constructs/transforms are child's play compared to the overly complicated features in Solidworks. Top marks!

Hi Sutts, well for a polygon modeler you might check out Silo or Blender.

If you do a web search for "blender terrain", you can find some stuff:

https://artisticrender.com/how-to-use-blenders-free-terrain-generator-ant-landscape-add-on/
https://www.blendermarket.com/products/true-terrain-
https://www.youtube.com/watch?v=Tf9qUs0rqik
https://www.youtube.com/watch?v=jyvbRJJTzY4

- Michael

Or this free one who has an UI Moi's like! ;)

And direct MOi <-->Rocket 3F objects export / import to the screen in the 2 ways with just a press key on an icon !
https://rocket3f.com

Thanks for the pointers, will check those out.

Here the same cube drilled above on a volumical spiral with the Flow Function!
As you see in less 30 seconds absolutly no problem & difficulties! :)