strange viewport rendering of imported 3DS geometry

#1

[color=white]I did some models in MAX and I’m now migrating to Blender. I decided to export some of my models to Blender for further processing. After importing the 3DS file, I observed that the resulting mesh does not render completely on the 3D-viewport … like some parts have flipped normals (but indeed they’re not).

The imported geometry also appear to be grand in size. Is there a difference in the way Blender interprets object scale and how can one overcomes this difference, if it exists? I’d hate to remodel my old models all over in Blender

I’m using Blender 2.5.2[/color]

#2

Try the importer from blender 2.49b, the importer from 2.52 was/is buggy, or try .obj format.
Make shure you always work with the latest build from graphicall.org for your system.

Cheers, mib

#3

Thanks mib2berlin. I got blender 2.49b installed. Blender hangs after the importation … sometimes, while in the process. This is bad

#4

Please don’t use the 3ds format, it is an old and bad format, use collada if you are using one of the latest blender builds or use obj, that works flawleslly :slight_smile:

Cheers.

#5

[i]

[/i]

Max 8 doesn’t export collada (correct me if I’m wrong). My experience is the same with .OBJ files.

Here is my present progress with 3DS:
My! The phenomenon got even more consistently bizarre.
I see that the object has been imported (scale is still huge), and I’m able to select it. I press “Home” to view extents and what do I get … Nothing! The object disappears completely. I tried blender 2.49b 3DS import script and was totally disappointed. Blender 2.49b just freezes indefinitely… No imports and no further “blendering”! There is something about the blender 2.49b import script that caught my attention: It is the dialogue box that said [color=YellowGreen]“Size Constraint 10.00”[/color]… and a tip saying “Scale the model by 10 until it reaches the size constraint. Zero disables”. So then, there is a size constraint in blender.

I need more insight on this. How does blender interpret measurements? Should I model with life dimensions or scale the models by a factor? I did my models in MAX to life size. Could that be contributing to the importation problems?

on OBJ:
Basically the same. I have not tried OBJ importation on 2.49b, but I will.

I suspect my case is linked with my graphic card or its drivers … or glx implementation in Blender. Might have to try this with a fresh linux installation … without the graphic card drivers or with Mesa. Blender sees the object but I don’t. Parts of it disappear on the 3D-viewport as I orbit. Zooming out makes every part of the geometry disappear. Its frustrating

#6

It is no way a hardware problem. Blender does not interpret units except physics. Create a cube and it is the size of 1.
You imported geometry which was probably done in such scale that the whole object is a view hundred units in diameter. Try rising clip end in view properties and lowering clip start, or just scale it down significantly.

P.S.
Quite a spirit to reinstall whose OS for just one application. Hope you didn’t started yet.

#7

I could be wrong but it does sound like the object is imported so big
that it can’t all fit in the view clipping plain/buffer.

In blender the convention is 1 unit = 1 meter for simulations*,
but otherwise you can really consider it arbitrary and set the
importers size constraint so that your import ends up in a size fit for the view-port clipping.

  • the convention is true also for SSS shader’s default ‘size’ factor,
    but it can be arbitrarily set.

edit:
dac77 beat me to it, one thing though:

:wink:

#8

You are right. I just wasn’t ready to run blender to check it.

I wonder if in future developers could add something like a scale indicator next to mini axis and simple indicator showing if some geometry is out of range?

#9

[i]

[/i]
Clipping plain/buffer? That’s new

[i]

In blender the convention is 1 unit = 1 meter for simulations*,
but otherwise you can really consider it arbitrary and set the
importers size constraint so that your import ends up in a size fit for the view-port clipping.

  • the convention is true also for SSS shader’s default ‘size’ factor,
    but it can be arbitrarily set.[/i][i]

[/i][font=Lucida Sans Unicode]I’ll be a good boy and go with convention. The model in question was done in MAX millimeters & to life size, so you can imagine the extents. E.g. imagine a human character at 1800mm height. Everything goes down by 0.001.[/font][i]

edit:
dac77 beat me to it, one thing though:[/i][i]
:wink:

[/i][font=Lucida Sans Unicode]Actually, someone else did … in another forum: here[/font].
[font=Lucida Sans Unicode]However, your response and dac77’s came with some details (the clipping view properties). I do wonder how blender will react if I overlook the convention and set the clipping in thousands of unit. Just wondering.[/font][i] You are right … the default size for a cube is 2units along x, y & z.

Now there are new concerns:
[/i]I observed that scaling in object level usually affects the transform matrix (…at least that’s how it works in MAX). So, I think I’ll scale in edit mode subsequently and preserve the (1,1,1) scale.

#10

you can just scale in object mode and then from the view(subdivision) header go
“Object > Apply > Scale” and it’ll apply’ the object scale(transform) to the mesh.

edit:
As for view-port clipping, you can change it in the 3D window properties panel(n-key).
It’s located under “n-key panel > View” as:

clip:
Start: “0.100”
End: “500.0”

Clipping space is needed as video-cards can’t display infinity after all
and as such the space has to be clipped to some practical extent.

As general rule of thumb the default size is perfect(ly fine) and in some cases for microscopic/millimetric/nanometric detail setting start to 0.05 or lower can be handy,
be weary as you make the start lower you may need to bring the end down as well.

Same goes for the End parameter as well,
as it rises you may need to grow the start param. along with it.

#11

Very Coooool :cool:

edit:
As for view-port clipping, you can change it in the 3D window properties panel(n-key).
It’s located under “n-key panel > View” as:

[i]clip:
Start: “0.100”
End: “500.0”

Clipping space is needed as video-cards can’t display infinity after all
and as such the space has to be clipped to some practical extent.[/i]

If convention says, “1 blender unit = 1meter”, then 500 End clipping is adequate for an animation scenery. My! … all that info was starring at my face all the while. Thanks guys

#12

If you need further help, I’ve got Max 9 and Polytrans…

#13

hope it’s not late…

at the moment i always use obj format. and import it part by part as it depends on the complexity of the scene -archtectural based. as to get the based point relatively correct, i’m importing dxf data. it works for me

sorry for my english

#14

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