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3ds max rounding errors?

Hi guys,

i'm having the following issue. I was asked to export an existing 3D scenario from 3ds max into the Unreal engine.
The original scenario had a scaling factor (system unit) of 1 unit = 1 centimeter.

The modell appeared to be too big after the export into the UDK editor. That's why I changed the scaling factor to 2.56 centimeter. Everything seemed to be fine.

I've used the new scaling factor to create the collision boxes but soon realized that this one still wasn't right. (The model contains houses as well).
I've changed it to be 1 unit = 1,524 centimeter.

Finally the dimensions of the houses were right as well. After importing my collision boxes again with that new scaling factor I noticed a slight shift of the points.

Does 3ds max do rounding errors so easliy ? It only shows 3 decimal places.

When I used a factor of 2,56, the x-coordinate is positioned at 214,634 and 83,842 with a scaling factor of 1,524. In theory, if I divide those I should get a factor of 2,56. Unfortunately, I don't get that. (214,634/83,842=2,5599818706614 )
That's a rounding error of 0,00001812933852.

That error seems to affect the collision boxes as they don't have the correct size anymore.

Is there a possibility in 3ds max to see more than just 3 decimal places or to tweak the options for import and/or export ?

I've also attached an image in case anything is not clear enough.

Thanks a lot
Varilux


ground.jpg

Replies

  • GeeDave
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    GeeDave polycounter lvl 11
    I definitely remember a thread on here a while back in which someone stated something along the lines of:

    "Use generic units and set home grid settings to 16, 8, 8"

    You can access the home grid settings by right clicking the snaps icon, there will be a tab for it.
  • Varilux
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    Ok, I tried it with the use of generic units. The result was the same. Why is the use of the home grid so important? Sorry, normally I just build objects. So I just work with modifier. The home grid helps to see what is up and down, left and right. But that was it for me, so I disable it very early. Are they important for the Engine?
  • GeeDave
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    GeeDave polycounter lvl 11
    Disable? I'm not sure how one even goes about disabling those settings. To my (limited) knowledge however, the use of generic units and setting home grid dimensions is so your grids match that of UDK. It won't magically transform a brokenly-scaled object into the correct scale, but it will make life easier for you in the future.

    Perhaps try posting in the UDK section:

    http://www.polycount.com/forum/forumdisplay.php?f=63

    I would imagine someone in there would be able to advise you better than I can.
  • Varilux
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    GeeDave wrote: »
    Disable? I'm not sure how one even goes about disabling those settings.
    Sorry. What I wanted to say is, that I turn off the grid (press G). What i don't understand is, why should I use the home grid? Maybe I work wrong. Someone told me he want a model of his house which is 10.12 meter height and 6.53 meter wide. So I build it. Can the home grid help me at this point?

    At the beginning I try the CryENGINE which was very simple with the export (1Unit=1 centimeter) and InGame it seems correct. With the UDK and a built scenario it seems not so easy to rebuild it. In the UDK documentation I've also read how to change his character (persons size, etc.). However, I do not know if that brings some disadvantages that later.

    If you felt attacked, I apologize me again. English isn't very easy for me. Thanks for your answers.
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