# Sandbox: Size limited?

#1

Hi everyone
I’d like to build a huge Mountain range with SketchUp. Unfortunately I can’t make a Sandbox wich is big enough (I’d like it to be some hundred squarkilometers big). there is always the message that there is not enough storage.

is that a problem caused by my computer or by SketchUp?
Is the size of the Sandbox limited?
is it even possible to build such a big mountain range?

#2

SketchUp doesn’t play well with models that are bigger than, say, a kilometer or two across. With bigger models, first, viewport clipping starts to appear, and, with very large areas, severe screen artifacts. It is a limitation of the way SketchUp uses the OpenGL 3D screen rendering system.

Anssi

#3

I think it might depend on the grid size. I created a 12 kilometer by 12 kilometer grid using a 50 meter grid spacing. This resulted in 12000 / 50 = 240 edges along each side or 240 x 240 = 57,600 grid squares total. Since each grid square is made up of two triangles and their edges, the entity count is much higher:

On the other hand, if your grid spacing is 1 meter, you would end up with 12000 x 12000 = 144 million squares or 288 million triangles and approximately 720 million entities. My experience has been that somewhere around 650 x 650 is about the largest grid spacing that can be readily processed (at least on my equipment).

#4

SU also, notoriously, has problems modeling very small geometry. The typical workaround is to scale up the geometry by some multiple of ten (so you can do the scaling on the fly in your head), like x100, to bring it into SU’s normal working range.

Your problem seems to have the opposite solution–you need to scale the mountain down by, say, .01 or .001. Perhaps the easiest approach is to set the unit of measure to meters and pretend you’re using kilometers (or set it to mm and pretend it’s in meters).

-Gully

#5

I found a grayscale image of the Earth:

and imported it into SketchUp (rendered by my free copy of Thea):

This utilized a 640 x 320 grid using 409,600 triangles. I was able to use the tape measure to set the “true” size of the x-axis dimension to 40,000 kilometers (the circumference of the Earth). However, the axes disappeared and other visual problems cropped up. When the model was nominally 640m x 320m, it behaved normally.

I think Gully has the right approach.