Geometry Export issues R2vsR4

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Rivaliant
Posts: 45
Joined: Mon Oct 09, 2017 6:43 am

Geometry Export issues R2vsR4

Postby Rivaliant » Wed Feb 14, 2018 9:25 am

I had brought this issue up in the old forms some years back now and i finally want to readdress it.

The reason why i bring this up is because for years now I have notice a huge loss in rendering quality of my work.

I'm still an avid user of Reality/Luxrender
But with the addition to Iray to Daz Studio I'm worried that luxrender has been left by the wayside and I really don't want to relearn a new system just to stay on track with my work.
But this is one issue i want someone to look into because it is a huge problem that seems to have been overlooked or was never confirmed to be a my only isolated issue

and that is the way Reality 4 Exports geometry into Luxrender
This is a table prop from Suite 2101 https://www.daz3d.com/suite-2101
that i noticed creates this issue
Image
This is what it looks like in Reality 2, easy enough


but this is what it looks like in Reality 4 with identical settings
Image
asides from the richer darker color to the texture aside
The outer segment of the table looks horrible mangled
this is repeated on Every render it is in

whatever difference Reality 2 exports geometry into Luxrender does not do this


i even exported the OBJ of just the table to see if Reality 4 does infact treat the geometry the same and it does
Image
with out the textures but with the shading color you can still see the outer rim segment is still not smoothed

What and where i notice this being an issue is on broad flat polygons such as interior segments of scenery such is indoor spaces
some times you just get segments of wall that are just Blacked out and these errors in geometry just seem to make the scenery smaller and uneven looking to the eye.
Needless to say it's an undesirable effect it has on your final product.

I have however found how to fix this.
Image
See how much prettier it looks now that the curvature of the table and the unwanted lines that had made it look like a target reticle has been alleviated.

what you want to use is Micro-facets. I hear talk that Micro-facets only work on flat geometry and sine flat geometry seems to only be effected here
we are in luck

but it won't work without a displace map image
So i had created a 1000x1000 px 50% Grey JPG image ( RGB value is 128 )
I'm sure any size would do
and also set the strength and neg-pos numbers all to 0 just incase
Image
Setting the Subdivision to 100 for micro-facets to insure a good subdivision resulted in the offending surface to smooth out indefinitely

another example when testing this fix out was a Dance Dance Revolution arcade machine prop i bought and downloaded off TurboSquid
(because i'm a total nerd and love me some DDR)
Image
the issue is using reflective material such as metal or even mirror really screws with the feel of t he object when this error shows its ugly face
The issue is the faces of the polygons then are pointing at unintended directions causing the reflections to not line up with expectation
This leaves the object and the final product robbed of any wow factor because your brain picks up on this lack of detail and fixes it self into that uncanny valley observation

The dance pads is self are obvious, but you can see it on the cabin itself around and In the bass speaker segment.
The inclosure is more full and and the fake depth of it is been fixed.
If you notice the reflection of the right neon ring parallel ends that come out of the cabin is missing in the error prone image at the bottom of the casing. or even the reflection of the left neon ring makes a P shape in the back plating as opposed to a mirrored reflection.
Image

again this just robs the final images wow factor that luxrender is known for

I had other issues regarding gemstone props of it auto smoothing with disastrous results

I know this post was long, but with the lack of updates i figure maybe it was time to address this and or get some answers

or if anyone has been having issues with this and needed a fix, i got you covered

Thanks for you time

PlatnumK
Posts: 122
Joined: Tue Mar 01, 2016 5:12 pm

Re: Geometry Export issues R2vsR4

Postby PlatnumK » Wed Feb 14, 2018 2:08 pm

Nice tip, I tried it on a prop where I should have smooth flowing edges but was getting jagged edges and can confirm that it works like a dream.

Rivaliant
Posts: 45
Joined: Mon Oct 09, 2017 6:43 am

Re: Geometry Export issues R2vsR4

Postby Rivaliant » Mon Mar 26, 2018 6:06 pm

case in point

since the forum won't let me post images large then 800px i just cut out the cube i was working with

Image

i wanted to do some volume testing and I ended up with a weird black plane that showed up when set to Null
(i turned the volume off)
Image

Image
and i also get this when i return it to a glossy material
Its now not the whole face but half of it ( this is interesting, that whole face looks like its producing a shadow on the ground )

i don't know why it does this

if you subdivide it in lower levels like 1 or 2 it kinda makes the cube look bulky and not smooth
Image

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sigstan
Posts: 437
Joined: Sat Jan 24, 2015 3:59 pm
Location: Denmark

Re: Geometry Export issues R2vsR4

Postby sigstan » Tue Mar 27, 2018 1:49 am

I've seen this one before, both when using volumes and in general use. I believe it has something to do with the way DS is creating primitives and how Reality reads these. It was not a problem in Reality 2.5, but with the introduction of Reality 4 it started appearing. Paolo has stated that DS is doing something wrong, when creating primitives, but personally I'm not sure this is actually the case.

Anyway, the best way to avoid this issue is to make sure, that you have divisions set to 2 or more, when you create the primitive using "New Primitive". This should prevent the artifacts from occurring at the cost of adding a few more faces.
/Sigstan

Rivaliant
Posts: 45
Joined: Mon Oct 09, 2017 6:43 am

Re: Geometry Export issues R2vsR4

Postby Rivaliant » Tue Mar 27, 2018 9:53 pm

maybe with primitives
But you can see with the opening post that whatever this issue is, it has to do with how Reality exports geometry with completely flat surfaces because its happen to full props like the table or even building geometry

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sigstan
Posts: 437
Joined: Sat Jan 24, 2015 3:59 pm
Location: Denmark

Re: Geometry Export issues R2vsR4

Postby sigstan » Thu Mar 29, 2018 3:34 am

/Sigstan

Rivaliant
Posts: 45
Joined: Mon Oct 09, 2017 6:43 am

Re: Geometry Export issues R2vsR4

Postby Rivaliant » Thu Mar 29, 2018 4:12 am

I also agree that Reality isn't export purely flat surfaces correctly
I have a feeling its sub-dividing them in a Bilinear fashion because the weird shadowing is similar to Daz Studios Bilinear SubD algorithms

I'm sure that weird looking bulk it has is also being exported in the Null, but because it isn't producing this black face its problem solved for that instant
But whatever issue is causing these errors in purely Flat surfaces is linked to what Ever change was done to how geometry is exported from Reality 2 to Reality 4

without the ability to look at the .ply files the exporter makes, I can't even compare the two

I'm for currents its some kind of bug or an unintended effect of a setting we have no control over


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