Ambient occlusion (AO) and it's usage Vray and 3ds Max

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3 May, 2011 RenderStuff (Staff Author)
3 May, 2011 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Hello, maksvel. Yes, for the creation of our lessons was the basis version of V-Ray 1.5. In practice, the most common version of the renderer now and for a long time it will be. To answer your question, the first thing worth mentioning is that the general principles and the general is all the Ambient occlusion . Ambient occlusion (AO) - is, in fact, create fake simulation of global illumination. Its essence lies in the fact that, based on the geometry of the scene, create a map of light and dark areas. Where adjacent objects, corners, recesses and other small parts of the scene will be podchernyatsya and the rest of the scene area will remain bright. Powered AO follows. From every point of the geometry of the scene on the hemisphere of her available vectors. Then, these vectors are tested for intersection with other objects or parts of the object scene. If one of the rays of the hemisphere intersects this point of the scene geometry, the exact color of the% D0 and becomes darker. Range, or rather the length of the vectors is determined by the radius parameter. The higher it is, the more distant objects from this point will uchuvstvovat in calculating its blackout. Here is how the scheme looks about these vectors: Where the bottom of the plane shows the surface of objects, and the top shows the geometry of another object in the scene. The dashed line shows the radius. So check every scene point and formed AO card or her love called AO pass. Not difficult to guess that if, for example, has been calculated point in any corner of the vectors that point certainly intersect with its facets that make the algorithm AO blacken point. And so on all the small details. Thus, a map of all blackened in such zones will be formed. Just this AO passes mixed in the final rendering, and is what you see, activating tick Ambient occlusion in the Indirect illumination. % A2o have renderer simply blackens all points of the scene in which the hemispherical vectors AO faced with the neighboring parts of geometry. Of course, that about any physical correctness or photorealism there is no question. The sole purpose of AO in the Indirect illumination, it's just a visual saturation stage small details designed to compensate for the lack of density of GI samples. It is not hard to guess that for photorealistic rendering true GI tuned and detailed maps, this function must be turned off. This is only a fake, helping to somehow seize the situation with low GI options. Here is a normal render, the AO map and render-mixed into it AO. If you look to the far right renderer, which is blended the AO, in general, yes, the details became a little more, but that's "surprise" - a place under the tulle, looks very photogenic not😁 By the way,renderstuff.com/mirror-3d-model-cheval-glass-gilded-wood-173/">3d model is carved woodwork classic mirror can be downloaded free of charge at the library archive. Regarding the Use camera path, we can only praise the developers, saying that it is one of the most useful innovations. in short, the activation of Use camera path will eliminate flikeringa on static objects when calculating the combined animations. that is, the animation fly-around, but with moving objects in it. in order to understand what exactly does this function, at least should be fully familiar with the technique of rendering of walk-through (Fly-through) and Dynamic (with moving objects) animation. But, responding specifically to your question, we treat Use camera path SUPER positive 👍 As for the filters, we have expressed our opinion on the very concept of their application in the article about the antialiasing . we advise not to use anti-aliasing filters in general, it concerns filter in principle. Both old and new😉


4 May, 2011 maksvel
4 May, 2011 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Thank you for the detailed answer! Indeed example gives an idea of ​​the AO, the truth is he is not in Irradiance Map, and in the Indirect illumination, but not the essence. 🙂


15 Aug, 2011 ASRockus
15 Aug, 2011 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Hello creators and visitors renderstuff.ru site! I have a question that is ambient occlusion? As I understand it, it's sort of a global simulation osvescheniya.No is how, where, and why, I do not understand. Could you explain how to use it and whether it is necessary. I think in some moments this thing is useful. Thanks in advance.


16 Aug, 2011 Anton (Staff Author)
16 Aug, 2011 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Hey. In fact the opposite is true, ambient oklyuzhen (AO) is not a global lighting method, on the other hand, a method of global shading😁Sut method in sleduyuschem.Predstavim, a plane and it should die. stage for ambient oklyuzhen on the surface of a cube is taken point [1], and its color is calculated. Nominally, the color of her white, but depending on the geometry of the scene, he may dim. ambient occlusion principle of the How does this happen? From the point beams. The same thing happens to other points on the cube surface points [2] and [3]. In the diagram I showed conditionally three points, but in fact the entire surface of the object to be littered with such tochkami.Itak rays come from all points and fly to colliding with other surfaces, collisions are marked with a red dot. If some of the rays emanating from a point contact with the scene geometry, no matter whether it is the geometry of the current object or objects - to calculate the color point slightly obscured. The more beams some point facing surfaces, the darker this becomes the starting point. If all the rays intersect with other surfaces, the point color will be completely black. calculation scheme shading in AO In our hypothetical example, only one of the three rays from a point [1] crossed the geometry of the scene (the plane). The other two beam - no, making a calculated point light seroy.Odnako why only one ray hits an object? It is logical to assume that all the rays will sooner or later be faced with some geometry. Then the point [1] will become even darker? No. Calculations of restraint beams blow only within a certain radius, which is obvious in the diagram above - radii shown yellow arcs. This not only eliminates confusion in complex scenes where a plurality of objects, just distant from each other and also prevents infinite calculation of intersection for the Rays, who flies into space and never with anything do not intersect. Of course, the radius value is simply set in the ambient parameters occlusion.Tak process of calculating the color dots on the surface of objects can be extended to as long as the colors are not calculated at all points. That is, until the calculated AO shader for the entire scene geometry, falling in the current kadr.Ambient occlusion is called global because it is applied to the entire scene, and exactly the same as on the cube, will be calculated and the color plane. In other words, the above points are littered with objects, not just the cube. model shading ambient occlusion On Ambient occlusion practice cube and the plane will look like this (item A): item renderer (render elements) ambient occlusion in the V-Ray Why AO shadowing confused with GI lighting Firstly, because they are often used in a similar role tselyah.Po fact Ambient occlusion -? it is cheap ( in terms of computing resources) replacement Global illumination. Naturally, AO, which is 100% a fake and comes close to the GI, which it mimics the behavior of the secondary light beams. However, visually AO still resembles GI. When the scene appear dark corners and "shade" under the objects (P) .All Secondly, AO as well as GI beams over the hemisphere of the calculated point. Remember chapter « Global illumination in computer graphics » from the lesson about the best setup V-Ray. In particular picture with a green beam of direct light and red hemispherical (hemispheric) rays of the GI. However, if the GI is secondary rays, that is a consequence of the primary emitted light sources, the AO is a global shading and all. AO Modern engines can already take into account the light sources feykovye not obscure places where the light source and fully applying shading to where direct rays do not reach the source. In other words, using the direction of light. But it's still very rough, especially given radius hemispherical working AO rays.
Why AO shadowing confused with GI lighting Firstly, because they are often used in a similar role tselyah.Po fact Ambient occlusion -? It is cheap (in terms of computing resources) Replacement Global illumination. Naturally, AO, which is 100% a fake and comes close to the GI, which it mimics the behavior of the secondary light beams. However, visually AO still resembles GI. When the scene appear dark corners and "shade" under the objects (P) .All Secondly, AO as well as GI beams over the hemisphere of the calculated point. Remember chapter « Global illumination in computer graphics » from the lesson about the best setup V-Ray. In particular picture with a green beam of direct light and red hemispherical (hemispheric) rays of the GI. However, if the GI is secondary rays, that is a consequence of the primary emitted light sources, the AO is a global shading and all. AO Modern engines can already take into account the light sources feykovye not obscure places where the light source and fully applying shading to where direct rays do not reach the source. In other words, using the direction of light. But it's still very rough, especially given radius hemispherical working AO rays. It should be understood that the GI is still secondary coverage, which only is color bleeding , whose redundancy is a parasite, but its presence in the scene just necessarily as a physical process occurring in the real world, and it adds a photorealistic renderer. While AO - it simply B / map global shading 🙄 Third, AO as well as GI is renderer component (A), which at the stage of the final rendering is superimposed with the other elements (B), as a result forming an image with pseudo-GI (C), and all proper .Vot theory AO, at least in general terms. Although far from the reality of the essence, Ambient occlusion is still a very cool thing. When used correctly, it is sometimes easy nezamenima.Ya suggest you digest outlined above info, I think you yourself guess how you can use the AO, but in any case, within this theme, we will consider various options and examples😉


15 Aug, 2011 ASRockus
17 Aug, 2011 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Hello Anton! Thank you for writing articles and explanations. Everything is very accessible explained, but to be honest, I have not yet figured how (knowledge is not enough), you can use it. However, in an Internet-based network, the lessons seen where this thing is used for rendering to texture, I am sure that it is not only its application and naznachenie.I still think the final render in Photoshop, you can apply image stock in any one of modes (if not right, straighten) .Bylo would be great if you're prompted where exactly (simple example), it can be used, and I have experimented with the screen and post it for discussion. Many think this topic is useful in the future! Thanks in advance. 🙂


3 May, 2011 RenderStuff (Staff Author)
17 Aug, 2011 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Let's start with th that modern render engines, in one form or another AO used in their work, that is, it is embedded in some of their instrumenty.V particular, the latest version of V-Ray, able to mix AO fake in the Indirect illumination. The eponymous book the Indirect illumination (GI) even has a separate section Ambient occlusion.Krome addition, the V-Ray has a specialized card Ambient occlusion, she called VRayDirt .VRayDirt - it is a parametric map, which is literally Ambient occlusion shading, which can be used directly in the shaders (materials) V-Ray. There are two slots, which determine the color point, hemispherical rays of which meet with an obstacle (Occluded color), and vice versa, from which rays do not meet with an obstacle (Unoccluded color), as well as the rest of the control algorithm function Ambient occlusion is fully zateneniya.My agree with the developers of V-Ray over the name of the map, which translates as virey dirt😁If you look at the last picture dice on the plane, it will be difficult not to agree that the AO is more like mud in the place of contact between the bottom of the dice and plane adhered there for many years, rather than the shadow of the GI 🙂 Although if only because the shadow can not be uniform around the subject, it can only fall into the dark side, in that time, as in the global illumination, that is, when the light hits everywhere, the dark area may be only AML cube, but not all its storon.Tem owls, however, that the dirt can be perfectly used in the materials. For example, the materials of classical furniture to simulate patined , when the flat part of the object have the same color, and small parts, mainly in the corners , dotted with mud or copper oxide, or simply an artificial patina imitating starinu.Vot Look at the material table 3d model for the head . It is easy to notice the characteristic of such furniture blackening finishes on small details. In particular, the panels around the perimeter of the facades. These darkening - no bitmap texture. This is all done shader, namely Ambient occlusion shader via VRayDirt.Takzhe card, you correctly noted that the Ambient occlusion can be used to postprocessing rendering . To do this, make a kind of so-called Ambient occlusion pass.Delaetsya it simple. Creates VRayLightMtl. At its core slot Color - VRayDirt.Zatem embedded map, the material is placed in a Override mtl slot scrolls V -Ray: Global switches . Also, turn off the other effects it is to render maximum bystro.Etot trick was simply a substitute for all the materials in the scene we created VRayLightMtl with AO - card VRayDirt.Posle what the scene is rendered, and the output we get a black and white shading Ambient occlusion map of the scene .Now you are ready to render kompouzingu.Finalny Ambient occlusion pass and throws in Photoshop and, superimposed on the final AO pass through one of the blending modes of layers, for example, Multiply. That's all. So there you have more details in the image, but then again, it is not always beautiful and the more realistichno.Vozvraschayas referred to at the beginning of the scroll Indirect illumination (GI), it does exactly the same thing, only automatically. That is, he simply on final render imposes Ambient occlusion pass , thus trying to compensate for the lack of detail at low settings secondary osvescheniya.Vot in general, and use the Ambient occlusion with V-Ray and, in principle, any other renderers working with this shading model😉


15 Aug, 2011 ASRockus
18 Aug, 2011 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Many thanks! I will experiment, but if that, then come back to the discussion😉 Thank you.


16 Aug, 2011 Anton (Staff Author)
18 Aug, 2011 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
We are waiting for the results! 👍


26 Dec, 2011 SERDGIUS
26 Dec, 2011 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Join all posts thanked for the resource, the second day can not come off, about the AO more understandable description is not met, although read enough about it on the Internet, many thanks and chewed on other subjects too directly what that enlightenment has come. I myself modelinogom vizom and takes about three years, little by little just to move through the jungle 3D incomprehensible and other complications associated with it. Not a lot of off-topic, but much to ask as much as possible to expand the Materials section (this is my most painful issue, rarely turns out to achieve satisfying results me), that I would like to examine is your description of the creation of shaders metals, glass, etc. poobschatsya well and in this regard, respectively.


16 Aug, 2011 Anton (Staff Author)
26 Dec, 2011 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Hello! All in your hands. Create a new theme in the discussions on the question that interests you, let on how to create this or that material and will communicate 🙂 Here is a typical example about how to create a material anisotropic steel: http://renderstuff.com/svobodnoe- 3d-obsuzhdenie-53-sozdanie-materiala-anizotropnoi-nerjaveyuschei -stali-v-vray / And there are those on mats enough, so do not be shy😉


16 Oct, 2012 Aleksandr
16 Oct, 2012 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Greetings! Please tell me how that's achieved such clear microghosts in the joints of the objects? Whether it is achieved AO layer in the post or is it something else? Thank you in advance 🙂


16 Oct, 2012 Denis
16 Oct, 2012 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Hello Alexander. It seems to me, such a result can be achieved with the optional rendering. Namely, the option Detail Enchancement. For more information on the settings and the principle of operation can look in Improving Irradiance map details .


16 Oct, 2012 Aleksandr
16 Oct, 2012 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Denis thanks for the tip. I'll try to use it. Casket, as they say. 😁


16 Oct, 2012 Denis
16 Oct, 2012 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Alexander is not the fact that I am right, it is so to speak the thoughts ... can not help but still try ... small details is working well, but that increase in rendering will also be present at the time.


16 Aug, 2011 Anton (Staff Author)
16 Oct, 2012 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max

Hello!

AO and IM affect the clarity and detail rendering , but to a lesser extent than, for example, the algorithm antialiasing or antialiasing mask with combined filter , because for plotting parts, actually meets antialiasing .

And that, for example, the Adaptive DMC stranded paired with Catmull-Rom, will give the right for clarity. Of course, the cost of this will render time 🙄 As for the joints, they at least need to do and not to rivet the neighboring facades back to back, and then outraged, why there are no gaps😁



16 Oct, 2012 Aleksandr
16 Oct, 2012 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Anton, but then your team wrote that in HDRi AA should be avoided due to the artifacts? As then? And about the joints in the models you are absolutely right. The joints and chamfer important part of our total 🙂


16 Aug, 2011 Anton (Staff Author)
16 Oct, 2012 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
😁 Our team wrote that the need to render in half higher resolution than the one in which you plan to use the final image. A sharpness of direct post-processing . But if such a question, it means that it was not heard or that option, for whatever reason did not fit. In general, yes, with HDR rendering , anti-aliasing filters should be avoided. So here it is necessary to choose a double resolution and HDRI or Catmull-Rom and LDR. But, by the way, and artifacts on the artefacts to appear at random relative to specific locations. So and HDR rendering, though they often arise, but nevertheless not always. Make the right choice in a particular situation, it is one of the main tasks of competent 3d visualizer. In any case, Adaptive DMC or Fixed may be used for any rendering😉 Put yourself to the Adaptive DMC Min subdivs 9 and Max subdivs 18. it has paid off😁


16 Oct, 2012 Aleksandr
17 Oct, 2012 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
What about the team wrote, because they do not know the author of the article. Can you e all team wrote? 😁, however, information about the resolution to be heard, but if "in-line" in the rendering of A4 is somehow to save time it is impossible to render 7000 along the long side. 😉 I'm afraid to imagine how many will take ADMC 9/18. : | Now I just do classical interior with lots of stucco and the question of definition and microghosts is very serious.


16 Aug, 2011 Anton (Staff Author)
17 Oct, 2012 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
The subject of visas, for example, I often render with ADMC 6/12 - tolerant (relative to AS). And about the team you are all right ponimash need to be special, to write and oformalyat these lessons alone, just sounded funny😁


5 Apr, 2013 Ilya
5 Apr, 2013 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
please tell me, so I do everything as written, but for some reason it does not always come out twisted configuration is not black and white picture and serochernaya. because of what it can be?


16 Aug, 2011 Anton (Staff Author)
7 Apr, 2013 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
This may be due to not correct gamma , due to the exposure of the scene or the brightness is insufficient self-luminous material.


29 Aug, 2013 Anton
29 Aug, 2013 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
How to achieve such an effect on the stucco using Ambient Occlusion?


16 Aug, 2011 Anton (Staff Author)
2 Sep, 2013 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max

Hey, I do not understand the question, or rather the question itself contains the answer and I am not clear what exactly do you make it difficult.

I assume that you know that a similar effect is created using the AO but do not know how to apply it.

The V-Ray only three main uses Ambient Occlusion:

- Making Blend material with a mask of the VRayDirt .
- Includes Ambient Occlusion, eponymous scroll zone V-Ray :: Indirect Illumination (GI).
- Separately render AO passage and post-processing imposes it on the final render, on the dates of your objects.



15 Sep, 2013 azuxa
15 Sep, 2013 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
The material used to map v-ray dirt in the bowl and a rectangular object, the results are different, can not understand the matter in the map settings or geometry. Help Board. : |


16 Aug, 2011 Anton (Staff Author)
15 Sep, 2013 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
VRayDirt - parametric map, one of whose operands is the main geometry of the object, however, on different objects with different geometry AO will look differently. Read more in this issue, from the very first post😉


1 Mar, 2014 Usco (3d modeling expert)
1 Mar, 2014 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max

Hello.
This is the answer (I apologize for a long time) to the post gus_ann, which was kindly provided with the necessary

Materials:
Http://en.renderstuff.com/pokritikuyte-pozhaluysta-3d-render-model-385/page-12/#7200

So: The meaning of all manipulations is to get just a black and white picture imitating shadows.

More information can be found here:
Http://en.renderstuff.com/chto-takoe-ambient-occlusion-ao-i-kak-ego-ispolzovat-v-vray-311/#dis

Cussion
Http://en.renderstuff.com/otlichiya-vray-1-5-ot-2-novye-funkcii-271/#954


Let's start:

In the [Render Setup: V-Ray] window, select the [Render Elements] tab.
Use the [Add ...] button to add the [VRayExtraTex] element, click [OK]. Select the added element, the bottom of the window will appear

This element. Click the [None] button opposite [texture] and add the [VRayDirt] card to it.
Then, without closing the window, open the material editor window and drag the added [VRayDirt] card to any

Free slot as [Instance]. The [Render Setup: V-Ray] window can be closed.
Now we can manage the settings of the [VRayDirt] card in the materials editor.
In the figure you will see two added elements [VRayExtraTex], renamed as [VRayExtraTex_AO-5cm] and

[VRayExtraTex_AO-20cm]


Consider the parameters of our card [VRayDirt]. In this example, we need only three parameters: radius, subdivs, and

Exclude ...

-radius - It indicates the distance (in the unit of scenes - in this example in cm) our future "shadow" will spread.
Pay attention - this distance will not be a solid fill of the shadow 5cm and a gradient one. If 5cm is specified, then the darkest part

"Shadow" will be in the "zero point of the beginning of the shadow" - (intersection / close location) of the geometry of the scene, after 2.5cm "shadow" will be 2 times

Lighter and finally at a distance of 5cm it will go white.
That's why I added two elements: [VRayExtraTex_AO-5cm] and [VRayExtraTex_AO-20cm], in them I configured the distribution of "shadow"

5cm for small objects (fillet, photo frame, bedside table) and 20cm for the bed and the shadow near the nightstand (avoid "flying" objects - the "shadow" under the bedside table is incorrect, because it "hangs" in the air). Naturally, you can not

And add only one element with the necessary radius.

-subdivs - This value is responsible for the quality of the "shadow" gradient. If after the test render (a small section) your "shadow"

Will be noisy - increase this value.

-Exclude ... - Here you select objects on which there will be no "shadow", i.e. These objects will not be obscured by the "shadow" and which you do not

Are needed for further processing. Here I added a chandelier and a plant. You could also add a curtain. Since the site with

The proxy-luster was calculated for the longest time, I generally excluded it from the render. To do this, I chose a PCM chandelier ->

Object_Properties -> clear the check mark [Renderable]


Now go to the settings of the renderer:
Open the [Render Setup: V-Ray] window. I turned off the light completely and did not use [Indirect Illumination] since Do not participate at all

In miscalculation, I assigned all the standard V-Ray material, I left the gamut as the author.
I will remind you that I do an additional render only for the sake of this layer. You can simply add this [VRayExtraTex] element to the

Your final render with your settings. Renderim:


If you used the V-Ray buffer, save the images by selecting them from the drop-down list:


The pictures are ready:


We proceed to postprocessing.



1 Mar, 2014 Usco (3d modeling expert)
1 Mar, 2014 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Let's get out of Katrinko left - right: To do this in Photoshop open our original picture. Top in a new layer add our render AO. Change the blend mode of this layer to Multiply (Multiplication). To add a layer to the AO inverted mask (C + Alt click on the button add a mask). Our layer will become invisible. To prove it, we have to paint over the white brush mask according to the places where we need more shade. Tip: If you hold down the Alt key and click on the mask - a mask will be visible in full screen, and you can edit those places that missed, White -proyavlyaet, BLACK -skryvaet. If the effect is too strong - lower the opacity (Opacity) AO layer: How are the layers and masks you can see below: the result to: after:


1 Mar, 2014 gus_ann (3dsmax vray expert)
1 Mar, 2014 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Ooooh! THANK YOU!


10 Nov, 2016 Iggi
10 Nov, 2016 # Re: Ambient occlusion (AO) and it's usage Vray and 3ds Max
Render in psd-manager, - and the desired layers, including the selected render items, just get on the fibers in one (psd) file (plus layers of the selected objects, materials, etc.) By the way, for example, by editing the " levels "in bed" blanket "(if in the above example in psd would have saved such a layer), it would be possible to get the same effect with much less body movements. There is another way to use ambient oklyuzhn - throw it to the light sources.


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