Full Version: MOI3D to Octane Render Tutorial

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Hi Phil, just some additional info on this one part:

you wrote:
> I also tried exporting this Cylinder as an LWO and using the MOI
> with Normals lwo import script listed on the MOI3D Resources web
> page, and it too creates a faceted cylinder upon import.

Actually what happens there is the normals are loaded (as long as you had welding turned off), and are actually used in the 3D realtime view in Blender which will have a non-faceted cylinder in it - don't get confused with Gouraud shading artifacts which are a different realtime rendering thing.

But if you then try to render it with Blender's default render engine, the renderer apparently decides to ignore the vertex normals that are present in the model and instead calculates new ones (which will be greatly degraded for CAD data) just for the rendering.

I actually didn't realize there was this bad problem with the Blender render engine until just now. I don't know why it does that, it is really annoying. Please don't use it as a model of how vertex normals should be handled, it's really very messed up.

Here for example I've found a post of someone mentioning this same problem:
http://geheim.blender.org/forum/viewtopic.php?t=13141&view=next&sid=41ba63d8dcc1ad464905c435d109c552

If you use a different render engine in Blender than the default one, or probably if you export your model, those good normals can probably get used. Anthony who wrote that LWO importer was using the Sunflow renderer, which ended up using the good normals, here is his original post about it:
http://moi3d.com/forum/index.php?webtag=MOI&msg=979.1

- Michael

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Hi all

Just to say:
obj files from MoI to (direct import) Thea Render = perfect result.

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From Rhino to Octane by Osiris

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Hi Pilou, those look cool! But if you examine it closely I think you can see some of the artifacts being discussed.

For example here it looks like a visible seam appearing in the shading:



And here it looks like a sudden jagged bounce in the reflection:




Those are the kinds of imperfections that would actually be gone if vertex normals were being handled properly. It kind of gives an appearance of bumps or creases in those areas when probably the actual NURBS model was actually silky smooth there.


It's really sad to have such great quality for many of the other aspects of the rendering, but have problems in what is actually a really basic area.

- Michael

Image Attachments:
octane_artifacts1.png  octane_artifacts2.png 

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sure :)

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Here is another really simple test - this one just has 1 single polygon in it so I don't think it can get any more simple than this.

I made a curved surface that looked like this:



But then meshed it with a really coarse angle setting to make just one polygon from it. But the vertex normals on the corners of that polygon will still be angled off to the sides (along the NURBS surface normals there) to give it the same kind of shading as the curved surface instead of it looking like a flat plane, here is what the mesh looks like when saving out from MoI:



Here is what it looks like when loaded into Cinema4D - note that even though it is a single flat polygon it has a kind of curved shading to it due to the vertex normals pointing off at angles:




The file is attached here as SingleCurvedPolygon.obj , can someone please load that into Octane and post what a rendering of it looks like? Does it look like a totally flat plane or does it have a gradient on it that looks similar to the original curved surface?

- Michael

Attachments:
SingleCurvedPolygon.obj

Image Attachments:
single_poly_vertex_normals1.png  single_poly_vertex_normals2.png  single_poly_vertex_normals3.png 

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Hi Michael

Unfortunately as flat as a pancake. I sure though it will be solved in time. I think this issue must be high up on the priority list for Octane now.

Jamie

Image Attachments:
michael test.png 

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Hi Jamie, thanks for testing that.

So yeah, there is absolutely no indication of the actual vertex normals being used there for the shading whatsoever.

It's pretty obvious that only the face normal is being used to shade it.

That would probably be a good example to send over, since it is so simple with just 1 polygon in it.


Did you use any particular import options into Octane for that render? There is something like a "Use smooth groups" option, was that option enabled or disabled?


- Michael

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I have posted it on the octane thread and pointed them to this thread as well. I tried all the options for using vertex normals, smoothing groups but the result was the same. I opened it in rhino and the vertex normals are visible. It really does seem octane is not reading them at all.

Hopefully they can get it worked out because the render quality and speed are great.

jamie

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Hi,

How is this flat polygon supposed to be shaded curved ???

all supplied vertex normals point in the same direction.

o object1
g object1
v 0.00000000 -0.00000003 3.13267816
v 0.00000000 0.00000008 -11.46117186
v 33.88950663 0.00000008 -11.46117186
v 33.88950663 -0.00000003 3.13267816
vt 0.00000000 1.00000000
vt 0.00000000 0.00000000
vt 1.00000000 0.00000000
vt 1.00000000 1.00000000
vn 0.00000000 -0.70710678 -0.70710679
vn 0.00000000 -0.70710679 0.70710678
vn 0.00000000 -0.70710679 0.70710678
vn 0.00000000 -0.70710678 -0.70710679
s 1
f 1/1/1 2/2/2 3/3/3 4/4/4

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I dont know how it works but see attached image one is the single poly michael provided the other is a flat poly. You can see the reflections are totally different. Also the other pic is the opengl viewport in rhino and it is showing the normal direction.

regards

Jamie

Image Attachments:
27-04-2010 12-54-19.jpg  single poly copy.jpg 

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Hi Radiance

I made a single flat poly in MoI. The vertex normals are totally different.

mtllib SingleflatPolygon.mtl
o object1
g object1
v 0.00000000 3.13267827 -0.00000008
v 0.00000000 -11.46117210 -0.00000008
v 33.88950729 -11.46117210 -0.00000008
v 33.88950729 3.13267827 -0.00000008
vt 1.00000000 1.00000000
vt 0.00000000 1.00000000
vt 0.00000000 0.00000000
vt 1.00000000 0.00000000
vn 0.00000000 0.00000000 1.00000000
vn 0.00000000 0.00000000 1.00000000
vn 0.00000000 0.00000000 1.00000000
vn 0.00000000 0.00000000 1.00000000
s 1
usemtl Default
f 1/1/1 2/2/2 3/3/3 4/4/4

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Hi radiance,

>>all supplied vertex normals point in the same direction.<<

They do not.

Check the "-"(negative) in front (of only some)of the values.

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Thea Render:

Image Attachments:
polygone_thea.png 

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Hello,

I got the same result as ycarry in TheaRender. If Octane doesn't pan out I can always wait to get GPU capability in 1.3. That kind of stinks since the new GPU is on it's way and from the videos I think I'll like the OR GUI a little better then TR.

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Okay, that's very sad. This dude cant tell the difference between Vectors? Is Octane using absolute values or something?

And further to the point..if you're the new kid on the block and you're in "Beta", dont upset your testers when they find a bug that saves you from your customers finding it in Production. Just fix the bug and thank your testers for finding it.

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Nice, I've been banned from the customer Octane forum :P

[QUOTE]

I've decided to refund you're license after reading your posts on the moi3d forum.
i spent 2 days working on a smoothgroup implementation to get your welded superball model rendered,
and yet you post such disrespectfull things...

[QUOTE]

I spent 2 days of posting examples/test/rendering comparaison ... well lets turn the page.

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That is surrealistic :)
Way to the perfection is some tortuous :)

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Michael's single polygon rendered in KeyShot. Matte clay material. Brightness and gamma settings at default.


Ed

Image Attachments:
keyshot test render.jpg 

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I'm speechless.

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