Looks great !

LWO is by far the best way to import MoI files into Modo now.
I still can see some rendering artifacts (see image 3 - Top) but it seems it's okay for 99% of the models now. There are some shading problems in 3D view (image 1) but they are not annoying (at least for me).
Modo 301 should be released very soon and Luxology mentioned that vertex normals will be (officially ?) supported in this version so I will wait to see if there are changes or improvements once 301 is released. For me, you can now concentrate on the release of version 1.0 and the documentation. ;-))

BTW; I notice that the materials are double sided and the smoothing angle is set to 20% for only two of the objects. The third one which had correct normals orientation has the default one sided material of Modo and a smoothing angle of 60%. Was this intentional (all three are open meshes).
(EDIT : Ooops ! I realize I selected the wrong material, so neglect this part of the message...)

And, maybe a dumb question, but if the support of vertex normals in 301 is better than in the current version, do you plan to deactivate (turn off) double side materials for LWO objects ?

And just for the fun and show the improvements over the recent months I enclose a rendering of the Cannon by Steph 3D. Export in LWO format with standard values (and N-gons). Much better than a few months ago, don't you think ! ;-)

Thanks for your dedication to the community !

Hi Schbeurd, thanks for testing it!

That cannon shot really shows off the shading quality improvement that having accurate vertex normals brings - it's looking soooo nice and smooth there. And having n-gons should make even the wireframe look really nice too! ;)

It was really frustrating before not being able to get geometry into Modo through OBJ, so I'm glad that there is now a good pathway.


> I still can see some rendering artifacts (see image 3 - Top)

I'm not quite understanding this one part - is there something wrong with the stuff circled in the upper-left view there?


> There are some shading problems in 3D view (image 1) but they are not annoying (at least for me).

Yeah, this appears to be a side effect of Modo not doing double-sided lighting for the realtime 3D view. Those darker ones are the meshes that ideally you would want to flip if flipping was working properly in Modo. I guess the best thing for now is to just ignore that since it works fine at actual render time, or try to close off the ends and build stuff as solids in MoI so that normals will get oriented to the "outside" automatically.


> And, maybe a dumb question, but if the support of vertex normals in 301 is better
> than in the current version, do you plan to deactivate (turn off) double side materials
> for LWO objects ?

Actually, I was thinking no, that it is probably best to leave this with the new way because it only sets double-sided lighting on open meshes. Meshes that are created from solids will not have that turned on.

Open surfaces generally sort of need double-sided materials for them to render in a more expected way...

Thanks very much for your testing support!

- Michael

>> I'm not quite understanding this one part - is there something wrong with the stuff circled in the upper-left view there?

Hum, my mistake... I didn't notice yesterday that this was a correct shadow cast by a "folded" part of the model. This became much more obvious today, watching the models at different angles. Sorry for reporting a non existing problem ! ;-)

Schbeurd

> Sorry for reporting a non existing problem ! ;-)

No problem, those are the easiest kind for me to fix! :)

It's better in general for me to get more reports (even if some turn out to be non-problems) rather than fewer and risk missing something.

- Michael

Hi Michael,

Thanks for the new beta! The vertex smoothing is working pretty nice now in modo 203!

I was testing an object and I've found a little problem. Here are some screen captures:

This is an IGES loaded into MoI:


And here is the polys previz in MoI (the object is Joined, by the way):



Another different problem with the same object...

Here's is before using Join:


And here after Join:



I've sent you the IGES file by email!

Thanks for your hard work, and for being so dedicated to the users!

Jacobo.

Hi Jacobo, thanks for reporting this problem!

It appears to be a bug in Join. It may be a difficult for me to fix it right away, but it seems to be related to the small size of some of the pieces. Some bits are around 0.003 units in size.

A lot of small edges around this size to be joined tends to confuse the joiner, it seems to get some edges reversed. The joiner comes from the geometry library that I'm using, it's not actually in my own code that's why it is not too easy for me to fix it immediately.

However, there is an easy work-around in this case - scale everything up by 100 times before you join it. That seems to avoid the problem area of Join and makes it work properly.

To scale, after you import the IGES file, select everything and run Transform / Scale. At the "Pick origin point" prompt, you can just type in 0 [enter] for the origin, and then type in 100 [enter] for the scale factor.

After you have joined the scaled up objects, you can then create a mesh without those problems you showed. You can also scale back down after the join if you want.

So this scaling-up trick is something that you can try if you see this problem again and the model seems to be pretty small in size.

- Michael

Hi Michael,

I've tried the scaling trick with this one and another objects that was giving
me some similar problems, and it solved those problems. Thanks!
I'm still getting a few holes in some parts of this object. Here's an screen
capture:




Another thing, and this is not like a real problem but something I'd like to
ask you about. I always get this kind of discontinuity in the number of
segments in some rounded surfaces. I was wondering if there would be
a way to get rid of that. Here's the same screen capture, but I've marked
the areas I'm talking about:




This is where that area is located in the object:



Thanks a lot for your help Michael!! :)

Jacobo.

Hi Jacobo, thanks for reporting these additional issues!

It turns out that new cracking is a bad side effect from doing the scaling.

There is a slight gap between the surfaces in that area. When scaling up, it increases the size of the gap to be large enough so that it will not join. MoI will only attempt to join together edges that pretty close together - within a maximum of 0.005 units.

If you look at that joined object in the normal viewport (not the mesh export display), if you look closely you can notice that the edges there are a bit darker than normal - this is because there are actually 2 edges there right next to one another since they did not get joined to one common edge. When 2 edges are drawn over top of one another they will appear slightly darker than normal.

However, I think that I've actually found a way to fix the original problem with join so that scaling will not be required.

I've made a patch for you here: http://moi3d.com/beta/join_patch.zip to install the patch, unzip the moi_lib.dll file and copy it over top of the old one in c:\Program Files\MoI beta Aug-1-2007 .

I have not tested every part of your model yet, but it looks like this should enable join to work properly without doing the scaling trick, so it should handle all areas properly now including the one that was broken by doing scaling.

Can you please give that one a try and see if you can get proper results without scaling now?


> I always get this kind of discontinuity in the number of
> segments in some rounded surfaces. I was wondering if there would be
> a way to get rid of that.

This can happen in areas where there is a change in curvature. That surface that you show there is curved with a slightly smaller radius (more tightly curved) near the middle than near the ends. The mesher tests each quad to see if it is within the angular tolerance - those ones that got additional subdivision were not within angular tolerance so they got subdivided more.

It's going to be a difficult thing to get rid of without also reducing detail too much in more irregular curved shapes. This kind of refinement helps create details in surfaces with smaller tightly curved bits in them. Maybe I can include an option in the future to disable this kind of refinement, I'll have to think about that one a bit and what kind of negative side effects that could cause.

You can turn the angle down and try to use "Divide larger than" or aspect ratio controls to try and more evenly divide things up instead of the angular test.

- Michael

Hi Michael,

Thanks a lot for the patch! I've been testing this object again, and a few others that
were giving similar problems, and it seems like it fixes that problem with Join.
I've tested the same operations with and without the patch, and I can see clearly
the difference. There's no need of scaling, and no holes either.
I'll keep testing just in case I find any problem with it.


About the segments continuity thing... do you think it would help (and it would be possible)
to specify the angle of tolerance... like a way to avoid the automatic refinement and let it be
spedified by the user. Like give it a margin in that angle of tolerance to keep the same number
of segments along a curved surface.
I'm not sure how that operation works, so maybe what I'm saying doesn't make any sense :)).

In any case, I know you have other priorities and still, you'd have to thing about that to see what
the side effects would be.


Again Michael, thanks a lot!!

Jacobo.

Hi Jacobo, that's great news! Thanks for testing that. I will use this update for Join then. I'm not sure if I will put out another beta or not yet, if not then this will be in there for V1 though.


I've tried having a margin for the angle before, but in the simple case what happens is an angle of 20 degrees with a margin of 5 degrees ends up being the same thing as an angle of 25 degrees. It basically just pushes the same thing to happen elsewhere.

One thing that I have thought about is to use a margin as a post-processing step after all subdivisions were complete. Maybe I could scan through and look for areas that had been subdivided just once from the initial base mesh, and glue those back together if the glued-together piece was within the margin angle tolerance. I think that might be the best way to clean up these areas. But I won't have time to experiment with that for the initial V1 release though, I have put this on my list of stuff to tune up later.

Here's an image to show you why these kind of subdivisions happen in the first place:



Without subdivisions, you can see that it would be hard to capture the detail for that little bump. It would be very wasteful to cover this entire surface with an evenly divided mesh that was small enough to capture that bump. Putting in subdivisions allows the mesh to gain detail only where it is needed.

The same thing is happening to that one fillet in your other model - it becomes more tightly curved in that one area in the middle (I think it was a variable-radius fillet), so MoI applies the same kind of logic to it to subdivide it to try and capture the detail of the curvature there. That's why it happens right now anyway.

- Michael

Hi Michael,

It's great that you have put that in your list! It would be great to have a way
to clean up more those areas. It would be great to have it as an option.
Thanks a lot for taking that into account to be included in a future version of MoI.

Keep testing!

Jacobo.

Hi Michael,

>>MoI will only attempt to join together edges that pretty close together - within a maximum of 0.005 units

Hmmm... it is different than the Join command in Rhino... there it is a two times of global modeling tolerance, isn't it.
Could you include all of this "accuracy" specific information into the MoI's help file? I admit, most of users don't need to know that, but many Rhino's users are suckled on technical terms...
I remember you mentioned three kind of tolerance so far.
Global modeling: 0.001 units
Rebuild tolerance for Loft and Sweep with Refit option: 0.01 units
Joining tolerance: 0.005 units

Thanks,

Petr

Hi Petr, that's a great idea, I will include this with the help file.

- Michael

I put up a new patch for this Aug-1 build here: http://moi3d.com/beta/Aug1_patch2.zip

This fixes a few meshing bugs and a few other assorted bugs.

To install the patch, unzip to get moi_lib.dll and just copy that over top of the old version in the Aug-1 version in \Program files.

EDIT: One other file also needs to be patched, copy the Sweep.js attached here over top of the old version in the \Commands sub-folder to make Sweep options work.

- Michael