Understanding scale

Hi all, I think that it is safe to say that I am not the only one who has a problem getting to grips with the scale of scenes! Any advice or links will be much appreciated.
I saw a post a while back where the person said that they had modeled their local shopping center and when it was finished it was suitable for ants. I thought at the time, why not select everything and just scale it up, I am sure to be missing something here?
I used my cad system to model the basic dimensions of a house so it was the real world size and then imported it into Blender, it seems tiny in Blender and the camera has to be brought in really close, should the camera settings be adjusted or is it just because Blender can handle such big scenes? Thanks.

what importer did you use to get it into blender? some of them have a scaling option.

you should scale your model up to a sensible size. in blender, architectural models work quite well at the scale of 1 blender unit = 1 metre.

you can use the “edge length” option in the “mesh tools more” panel (F9 edit mode). with edge length on, pick an edge on your model and see how long it is. then scale up the whole model accordingly. when you are happy with the size, use ctrl+A (object mode) to apply the scale to your object(s)

Thanks, I like the tip about 1 blender unit = 1 metre. Imported my model in obj format, I think most of my confusion comes from working with engineering cad systems where you have total control over scale.

I reversed the process and exported the Blender cube that measures 2 Blender units and imported it into my cad system, it measures 2mm exactly so 1 Blender unit is 1mm in the real world? Would I be right in saying that models can be scaled to suit visual needs without any problems or does scaling have negative issues on certain things? I have been using obj format which has no scale options only a limit when importing.

You want to scale your imported model to the Blender scale of 1 unit = 1 meter. Some external render systems use that unit assumption when calculating light based upon distance. It is fairly common for character models to assume this scale as well although I have seen characters produced at arbitrary scale and it can cause problems fitting them into a “real-world” scene.

If you know you are not going to use an external render system, then scale may not be that much of an issue. When I import models, I leave the default cube in my scene and use that as my 2-meter measurement device. It is a good guide for roughly scaling architecture door size to real world people.

Great tip about using the cube as a guide, the 1 unit = 1 meter makes sense. Cheers for taking the time.

The obj import script for blender has a dialog which includes a ‘Clamp Scale.’ The default value is 10. If your model is very large, then the imported object will be scaled down to a size that you may not expect.

You can disable this scaling by setting the Clamp Scale value to 0.

I did see that but only recently so that is the reason why the building is so small, start again or scale up?

I used to measure a known length using “Edge length”.