Hi Michael,

>>I'm not sure if I really understand your point about "in the real world"....<<

"In real world", = not a computer simulation/render, actually outside in the world :)

I have managed 15 minutes to make part of the model, will finish the section off (if time) when I get back from city centre.
Monday morning blues on a Tuesday :)

- Steve

Hi Steve,

> "In real world", = not a computer simulation/render,
> actually outside in the world :)

Uh ok, but the discussion here is actually about rendering...

You said:

"In real world, most reflections are not perfect as most surfaces are not perfectly smooth."


Was I supposed to interpret this as just some random fact completely disconnected to the discussion at hand?

I took it to mean something like: In the real world most reflections are not perfect, so it's ok for them not to be perfect in a rendering as well.

- Michael

Hi Michael,

I wish I had as much spare time as you to continue this fruitless discussion on what "real world" is, but I have not.


- Steve

Hi Steve, well I understand what the real world is.

What I don't follow is the purpose behind you bringing that up - were you trying to make some correlation between the real world and what a rendering should look like, or not?

If your comment had nothing to do whatsoever with the actual discussion, it might be better to just leave it unsaid.... It's pretty natural for someone to assume it had some kind of intended relevance to what was being discussed.


I have to admit, I'm pretty confused about a lot of things in this thread, like what is the motivation to do all this work to reorganize all the polygons when the ones that were just directly saved out from MoI with the accurate vertex normals on them generate an already perfect looking rendering.

I guess some of these things will just remain mysteries to me.

- Michael

Being a newcomer in these forums I didn't want to jump in, but after following this thread for a few days let me just praise Michael's composure in a discussion that might have stopped at post n.85 (or even before).
Reading some posts I had the feeling that people is speaking different languages or just refuse to understand. Meh!

Hello Michael,

>>I have to admit, I'm pretty confused about a lot of things in this thread, like what is the motivation to do all this work to reorganize all the polygons when the ones that were just directly saved out from MoI with the accurate vertex normals on them generate an already perfect looking rendering.<<

As I put forward earlier in the thread, I make models with quads due to that is what is wanted. I do not turn around to a customer and tell them "you really dont need that" and send them a model with n-gons/tris, then say, well it renders perfectly. If I did, then I would lose the work/contract.


- Steve

Well if the poly flow is so important then just use a poly modeler, where the toolset is all about pulling and pushing vertex.

Hoping that a nurbs package like MoI will output full quad sub-d ready mesh is just science fiction :P.

The problem with MoI meshing is that sometimes, the result is so close to a "perfect" topology , it gives the illusion that with some extra work (from Michael) the model can be used as a subd cage.

Hello PaQ,

>>Well if the poly flow is so important then just use a poly modeler, where the toolset is all about pulling and pushing vertex.<<

Some models are easier for me to create in MOI, and then cut them up to give what I want. So why would I be pushing vertex around when I have no need to? I look for the easiest solution for the output I want, not be told what tool to use that may then make the job harder. Maybe just me.

>>Hoping that a nurbs package like MoI will output full quad sub-d ready mesh is just science fiction :P.<<

There is certainly little hope of that if a mesh cannot be created without tris. But I have not put forward an expectation of such.


>>The problem with MoI meshing is that sometimes, the result is so close to a "perfect" topology , it gives the illusion that with some extra work (from Michael) the model can be used as a subd cage. <<

Now you are just being silly.

I will only make one more post to this thread, and that will be the result of my render test, once I have the section done.

All have a nice day.

"There is certainly little hope of that if a mesh cannot be created without tris. But I have not put forward an expectation of such."

There is an option to output quads and ngons. Not a triangle in sight.

Why sub-d a mesh created from nurbs? Sub-d is to create the kind of curved surfaces that are already in the nurbs model.

This thread has me baffled. The only reason to use all quads is if you are doing character animation and skinning and need to control where the bends in the mesh occur. Even then triangles usually work if they are in the right place.

Nurbs modelling is not the tool to use to create character skins.

>>There is an option to output quads and ngons. Not a triangle in sight.<<

No there is not. There is an option to output "N-gons" which will produce an output of N-gons, quads and tris. Even Michael stated earlier that it is not possible to output without tris.

Well my last post.

This is a section of that model.

Render of vertex normals



Render of smoothing.

Hi Steve,

> No there is not. There is an option to output "N-gons"
> which will produce an output of N-gons, quads and tris.
> Even Michael stated earlier that it is not possible to output
> without tris.

When you use "Output: N-gons" it outputs the underlying n-gons that were created by the refined surface intersected with the trimming boundaries, without doing any further tessellation of them into triangles.

The only way that you will get a triangle with that option is if the underlying surface fragment is actually a triangle itself. For example if you create a triangular plane, then that will create a triangle in that kind of situation.

But on any typical CAD model that will be pretty rare.

The n-gon option produces polygons that essentially follow the same topology as the original NURBS model - it has quads that follow the UV structure of the NURBS surfaces, and those quads are trimmed into n-gons where they intersect the trimming boundaries.

So for example in a case like the original block where there aren't any triangular trimming boundaries, absolutely no triangles are created:



If you have some utterly bizarre goal of wanting to have no triangles in the output mixed with n-gons, even when a even when a triangle is the most accurate thing to be created to fit on a triangle in the original CAD model, then I would suggest creating such meshes by hand in a polygon modeler - that will allow you to custom make the polygon layout to follow whatever particular odd goals that you might have...

- Michael

And just to clarify:

> Even Michael stated earlier that it is not possible to output without tris.

This is not accurate as a blanket statement. For example the block model posted earlier in this thread can be output without any triangles, here it is again:




If your model actually has a triangular plane in it, then it will naturally generate a triangle in the polygon output there as well, since a triangle is the best kind of polygon to fit on a triangular trimming boundary.

- Michael

Hi Steve,

> I do not turn around to a customer and tell them
> "you really dont need that" and send them a model
> with n-gons/tris, then say, well it renders perfectly.

But guess what - it is actually true that your customer does not really need that at all.

They are not gaining anything by having you spend a ton of time trying to reconstruct the model, and in many cases it will take you an enormous amount of time to make something that renders with no glitches in it. Meanwhile the original model just exported directly from MoI already renders a perfect result with no glitches. It's far more likely that all your extra work will actually introduce artifacts and since rendering the original model is completely glitch free already there is no chance that you are actually going to be improving the model.

So you're doing a bunch of work for potentially worse results. The best case scenario is that you're doing a bunch of work for the same result. Either one of these is a big waste of time and is fairly ridiculous.

Maybe you need to find some way to educate your customers better so that you don't have to do a lot of work for no purpose at all.

Your situation is fairly unusual because for most people doing a lot of work for no actual gain is a nonsensical thing to pursue.

- Michael

Hi Steve,

> Well my last post.

> This is a section of that model.

> Render of vertex normals

> Render of smoothing.


Looks pretty good! It's hard to tell in detail though with only looking at a single view angle, reflection imperfections are easier to notice when moving the model around some.

But anyway, great job doing a bunch of work to get the exact same rendered result as before.

For most people though doing a bunch of work to get the same result is completely pointless.

- Michael

And really this thread has become pointless as well, I'll close it so that nobody has to waste their time on it anymore.

- Michael