Author Topic: [deleted]  (Read 7622 times)

2014-04-15, 04:12:05

Strawberry

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[deleted]
« Last Edit: 2017-03-26, 14:22:20 by Strawberry »

2014-04-15, 07:51:54
Reply #1

Tanakov

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Im not sure what are you suggesting to the developers, but if you like stronger shadows goahead and use the proper pass to enchant it.
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2014-04-15, 10:16:18
Reply #2

Ludvik Koutny

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I'm very impressed with this plugin.

This is free, photo-realistic, fully integrated into 3ds max. very easy to use. light is good. colorful. faster than Vray.

I saw almost of images in the user's gallery. But I found a little artificial part of the images. The shadow seems not fully expressed. Bright side is almost perfect. But Dark side or the corner is artificial because of lack of shadow and reflection. It is very subtle. But it makes the image 2d-like.

Corona is more colorful and vivid than vray and maxwell. If shadow and reflection is better, corona will be the best renderer!

There's nothing wrong with the math in Corona's core. So what you see is ALWAYS up to users, and how they approach scene creation. Too bright materials often tend to wash out both shadows and reflection. But that is not problem of Corona, but skill of particular users.

Or you are just used to old over-exaggerated ambient occlusion look with fake shaders.

2014-04-15, 11:24:36
Reply #3

Strawberry

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[deleted]

« Last Edit: 2017-03-26, 14:23:07 by Strawberry »

2014-04-15, 12:57:24
Reply #4

Ludvik Koutny

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Things look that way because users made them look that way.

Get a scene, and render it with both Redshift and Corona, from exactly same camera, with exactly same material (may be just 50% gray for purpose of testing) lit by exactly same HDRI with exactly same orientation, and having exactly same exposure set up (preferably just no exposure control and linear output) and you will likely end up with nearly identical results.

2014-04-15, 14:34:20
Reply #5

Ondra

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The examples look IMHO correct - in the first one, the floor is white, so there should be no shadow, in the others, the geometry is not IMHO actually intersecting, so there is some gap.

But I would appreciate some comparison tests between Corona and other renderers ;)
Rendering is magic.
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2014-04-15, 15:28:08
Reply #6

Captain Obvious

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Dark corners in real life isn't shadowing; it's dust and dirt collecting. For realistic results, you need to texture stuff like that.

2014-04-15, 16:07:41
Reply #7

maru

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Ad 1. This situation may look unnatural because in real life it hardly ever happens that two planes meet at perfectly 90 degrees plus there is no gap between them. So this is more of a modelling problem than renderer's fault.

Ad 2. If this object is not above ground, then the lack of shadow is probably caused by the light source being perpendicular to this object.

Ad 3. You are showing places with objects hovering above ground, which is a different case and it would most likely look the same in Corona.

If there are any lighting inaccuracies, I would guess they are caused by HD cache's errors or some strange scene setup - some users upload pictures that look like with ambient light, I'm not sure what causes this.

2016-02-07, 00:50:47
Reply #8

jamestmather

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I find the same thing - there is a lack of fine detail shadows in the points where objects meet each other - is this something I'm doing wrong? I've noticed in the wings of a biplane connecting to the struts - in Iray these seem to have a definite connection but in Corona they seem to float. What can I do about this?

Thanks


2016-02-07, 01:48:27
Reply #9

SairesArt

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I find the same thing - there is a lack of fine detail shadows in the points where objects meet each other - is this something I'm doing wrong? I've noticed in the wings of a biplane connecting to the struts - in Iray these seem to have a definite connection but in Corona they seem to float. What can I do about this?

Thanks
There should be no shadow in these corners, a shadow is physically incorrect.
Thatswhy there is vray ao built in just with a check box, since this is an often wanted fake to add detail.
You can add CoronaAO and just shade the corners.

But corona is setup to not use or rely on fakes and deliver physical accuracy, where sometimes this may collide with the wish of some to adjust non physical correct aspects of an image.

On the bright side, with the well implemented embree kernel corona AO is the fastest AO I ever worked with, excluding GPUs which always win in that regard, but still its very close to those.

2016-02-07, 02:32:02
Reply #10

jamestmather

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Sure - I guess - compared to Iray it looks like things are floating to me and slightly unrealistic. Is there any way to get the AO in the render? Or does it require a post composite step.

2016-02-07, 13:46:20
Reply #11

SairesArt

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Sure - I guess - compared to Iray it looks like things are floating to me and slightly unrealistic. Is there any way to get the AO in the render? Or does it require a post composite step.
Currently only post.

2016-02-07, 13:52:20
Reply #12

Juraj

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While everyone correctly suggested there is minutiae of details happening in real-life, varying angle, slight offsets from geometry standpoint, dust/grime/etc.. from material standpoint,
I too have wondered that while I agree math is mostly always correct (though there are often exceptions, just remember the darkerning material edges), I wonder how complete it is, and if it would
be able to converge to absolute reality, if the user input was inhumanly perfect.

Even such simple stuff as GI caustic dominate our interior lighting in real-life so strongly that CGI will always look wrong, no matter how perfectly rendered without it. And that is just single factor, that
are many others such phenomena. One other is tailored BRDF since some materials behave too uniquely to light to be able to be correctly expressed by common model.

So, I think some user here, are maybe too quick to fault the user. Yes, some are too quick to fault the renderer too, but this is renderer's forum we should all strive for the rendering engine to be perfect alongside improving ourselves.

I've kep adding tons of detail to my wall modeling, and lot of complexity to my wall shaders at time, and I have never achieved even remotely similar results to walls that I am staring into everyday. It's not even close. Maybe to some,
but I've been looking this sort of detail for years and I can still see massive difference between reality and even the best available public pathtracers (only talking about shadow expression, not scene look). So far it was only the utterly slow and unflexible Maxwell that got decently close.
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2016-02-07, 14:34:48
Reply #13

Ludvik Koutny

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Sure - I guess - compared to Iray it looks like things are floating to me and slightly unrealistic. Is there any way to get the AO in the render? Or does it require a post composite step.

Make sure you are using material of exact same brightness in iRay when comparing it to Corona. That's the first huge difference. Second one is that Corona by default does 25 indirect light bounces. Iray may do less, and that's what could cause the darkening. Best thing would be to post images, so we can better see what's going on.

2016-02-07, 15:35:19
Reply #14

jamestmather

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Am I to assume then that like Iray that the materials need to be 0.7 in brighness otherwise they render overbright?