What is the overall size of your model?

- Michael

1.5 meter x 1.2 meter.

I'm also using MoI3d to model environmental props (walls, structures, etc). So the scale is sometimes much bigger than that. I've been eye balling things for a while, but recently, precision had become an issue when dealing with the grid settings and exporting models to other 3d packages. This is why I am curious about all this and want to find a way to reliably match the grid and scale setting from MoI3d and other packages.

Hi RD, in that 1.5 meter x 1.2 meter overall size are there going to be any details in it that are at the 1mm size?

Because that's a pretty tiny distance in proportion to the full object.

Maybe having one grid block as 1 centimeter would be a good setup.

You could do that by having these settings:

Grid size = 10mm
Snap size = 10mm
Grid sections = 150

- Michael

Hi RD,

re:
> I'm also using MoI3d to model environmental props (walls, structures, etc). So the
> scale is sometimes much bigger than that.

It's generally not a good idea to have objects with very large coordinate values in them.

It tends to degrade the precision of arithmetic done with floating point numeric values.

So don't set up things like an object 100,000 units across with units = mm, it would be better to use meters for the units or have the model at some scale factor instead of having very large or very small numeric values.

- Michael

When dealing with real life hard surface objects, such as mechanical components, I often have to use mm. So switching to cm wouldn't be a good option. And with my current workflow when I create larger pieces of an environment set, such as walls and structures, I often have many different pieces inside the same file. So, having the grid extend to these pieces, is very important since I don't only focus on one piece at a time in the same scene. In most other packages, extending the grid so that it is available when focusing on other elements in the scene, has never been an issue. I understand of course that this is probably not the way that MoI3d was intended to be used. Just sharing my personal experience with it, for your consideration.

Thank you.

Using your current example, what would be the best settings for the Grid and the Snap options to be able to see the grid and to be able to snap on mm while setting the base unit to meter in MoI3d?

Thank you.

Hi RD, you can keep your units in mm instead of cm for this case but what is it that you're trying to gain by having the grid displayed in 1mm blocks? it's just too tiny in relation to your full model size.

If you want the grid to be spread out over a larger area then the simplest way to do it is to make the grid size to be larger, like set grid size to 10mm. You can leave everything else including the actual grid snap to 1mm .

That way you'll have a few hundred grid lines being displayed instead of a few thousand lines being displayed.

- Michael

Hi RD,

re:
> Using your current example, what would be the best settings for the Grid and the Snap options to be
> able to see the grid and to be able to snap on mm while setting the base unit to meter in MoI3d?

If this is for your case with the object being approx 1.5 meters across, you don't need to set base units to meters, you can have units = mm and set the grid to:

Grid size: 10mm
Snap size: 1mm
Grid sections: 150

If you want to make the grid spread out over an even wider area then it's best to just increase grid size alone and maybe grid sections a little but not by some enormous amount.

- Michael

"what is it that you're trying to gain by having the grid displayed in 1mm blocks? it's just too tiny in relation to your full model size."

I would like to see the grid at that scale and be able to snap to it.

Well, I can snap to it, but the grid is not visible at that scale. I guess this is what I am trying to say.

Anything below Grid Size 6, and the grid disappears.

Hi RD,

re:
> I would like to see the grid at that scale and be able to snap to it.

I just don't recommend doing it, it's not very practical to have an enormous number of lines.

You can set the actual snap to whatever you want though. That's why grid size and snap size are separate settings.

- Michael

Hi RD,

re:
> Anything below Grid Size 6, and the grid disappears.

Can you maybe show me a screenshot or send a model file so I can better understand what you're seeing?

- Michael

"You can set the actual snap to whatever you want though. That's why grid size and snap size are separate settings."

Please correct me if I am wrong, but this means that I can't set the grid to be visible when dealing with such small scale settings? I can snap to these settings, but can't get visual confirmation using the grid?

Thank you.

Hi RD,

re:
> Please correct me if I am wrong, but this means that I can't set the grid to be visible when
> dealing with such small scale settings? I can snap to these settings, but can't get visual
> confirmation using the grid?

The visible grid would be spaced out wider than the snap points. You'll get visual confirmation of the snap by both movement happening in jumps and the XYZ coordinate input showing the current coordinate value in whole numbers.

If you are going to do some work for a while in a particular small region of the model you can reduce the grid size for a while and relocate the grid if needed by using View > CPlane.

- Michael

"If you are going to do some work for a while in a particular small region of the model you can reduce the grid size for a while and relocate the grid if needed by using View > CPlane."

Ah!

This is what was wrong with my workflow when using MoI3d. I understand now. I just assumed that the Grid settings would work under any circumstances and also when switching to other components inside the same scene.

Thank you Micheal, I think that this is the answer that I was looking for, to better understand how to work with the Grid settings inside MoI3d.

The way i would handle this would be to setup an "assembly" type workflow.

So MoI allows you to launch multiple, concurrent sessions. I would have one file with my overall scale. Then others can be created for whatever the current need is.

Copy and paste between the 2 works like a charm.

So with this, i can have a 64 story building, and model a tennis shoes shoelace eyelet, on the 34th floor, next to the cup on the window sill......

That's a good idea. Thanks for the suggestion.