GI Engines VRay 1.5 tutorial

18 Feb, 2011 renderstuff (Staff Author)
This article is written for V-Ray 3d rendering plugin version 1.5. You may find that some particular interface options have different names, are implemented elsewhere, or not applicable for the newest V-Ray and another software. Regardless of that, current article is written in educational story style and can be useful for anyone interested in 3d rendering concepts and methods. To get the up-to-date interface manual for your software, please refer to the official documentation.

Hello everyone!

In the previous two tutorials about IM and BF engines, LC and PM engines, we met with all four algorithms for calculating the GI in V-Ray. It is time to decide which of them are best for calculation of the global illumination.

This tutorial answers the following questions:

- Which GI rendering algorithms are best in Vray?

- Which rendering engine should we choose for primary bounces and why?

- With what engine should we render the secondary bounces and why?

- What problems exist in GI maps and what should be done to eliminate them?

- Why does the noise or dirt on the fine detail of the scene appear?

- How to get rid of the smudges in the corners and on the cornices?

best v-ray engine settings 2.4 by renderstuff

Choosing GI engines

Despite the seeming abundance, the choice is quite definite.

Photon map we cut off immediately for described in the previous tutorial reasons.

The most universal, capable of solving any problem is, of course, the Brute Force algorithm. However, the lack of built-in adaptability and the monstrous resource use due to this, just do not leave BF a chance to everyday use as the GI rendering engine. Sometimes, a tenfold increase in the calculation times at the same visual quality that optimized engines give is simply unacceptable in almost all situations. Only in some situations, when optimized engines simply cannot cope with appearing artifacts, which are actually because their optimization, the use of Brute Force can be reasonable.

Narrowing the choice to two algorithms Irradiance map and Light cache, it becomes quite simple :)

Comparing the working algorithms of IM and LC described in the previous tutorials, it is easy to understand that the quality of GI maps, obtained by IM, is significantly higher than the quality of GI maps, obtained by using LC. This is because, despite the partial formation of the result by interpolation, IM’s adaptability IM is able to calculate the GI with greater accuracy in important areas of the scene. While the LC only determines the color of GI for sampling areas in the form of mosaics, indiscriminately dividing scene on them.

Of course, we can significantly overstate the LC settings to obtain a result comparable to the visual quality of the IM. But, in this case, the LC computing time will inevitably increase. This approach will smoothly rollback us in the direction of Brute Force, practically bring to naught the difference in calculation time between LC with strongly raised settings and BF. In addition, the consumption of memory and problems with load distribution on all available system threads for a large LC map will also be a very significant drawback.

Irradiance map algorithm calculates the softer compared to LC GI map. The final render comes out more pleasant, without noisy GI. That is why IM should be used as an engine for global illumination rendering.

 However, we should not forget that V-Ray divides the indirect illumination for Primary bounces and Secondary bounces. Returning to the features of IM, we know that the Irradiance map, in principle, cannot be set as the Secondary bounces GI engine. Given all the above, we simply have to select the Irradiance map as the only GI engine for calculation of the Primary bounces.

Think you may have guessed at what engine for Secondary GI bounces will the choice fall :)

Light cache algorithm is rougher than the IM algorithm. However, as we already know the effect of secondary GI bounces on the general lighting is less important than the influence of the primary GI bounce. It is therefore the less accurate LC perfectly copes with the task of rendering Secondary GI bounces. In addition, its function Show calc. phase, which generates excellent previews, is simply irreplaceable. Light cache algorithm should be surely used in the universal starting V-Ray configuration; of course, Light cache should be selected as the GI engine for Secondary bounces.

Common GI issues

Now, when we are done with all available V-ray GI rendering algorithms, decided on how they work and have chosen the most rational and practical to use, it is time to consider the possible problems and their solutions.

In general, global illumination has just two major problems, more precisely the two main types of artifacts. They are noise and dirt. Oddly enough, but the causes of appearing and ways to eliminate noise are completely trivial. The cause of these common problems is the lack of GI sampling quality. The HSph. Subdivs parameter in Irradiance map and Subdivs parameter in Brute force and Light cache are responsible for this. Increasing the values of these parameters will reduce the amount of noise on the GI maps and, hence, on the final render. We should not stop on this kind of artifacts.

But the cause of the smudges on the rendering or as they are called "flakes", which are often cover the fine details of the scene, is worth studying in more detail.

Dirt, namely, black, gray, and even the bright spots may appear in the GI map, created by the IM algorithm. This occurs because of insufficient detail of the irradiance map.

flakes smudges bray irradiance map ugly low high quality
Two renderings of the test scene right corner, which is out of reach of the direct light rays and lit completely with the indirect illumination. Left image shows the unpleasent artifacts in the form of dark and light spots at the fine details, in particular on the grid. The right image with the reise Max rate value has no such issues even in the smalles scene details.

Look at the picture. Do not need to look very closely to its left part to see the terrible dirty spots on the grid. Any interior rendering specialist is very familiar with those. Especially clearly these artifacts appear in places where is no direct light and in highly-detailed scene areas, illuminated only by the indirect illumination. For example, they are often on the quaint white ceiling cornices, which are in deep recesses of the ceiling.

Lack of understanding of this problem nature, has led to appearing of extraordinary ways to fight it. The simplest of them is a blind rising up the HSph. subdivs for IM, Subdivs for LC, changing units, sampling sizes, and just sky-high increase of Subdivs parameter for key light sources in the scene. More targeted was a significant overstatement of interpolation in order to blur the GI. However, the most convoluted methods consist in the following. The camera, intended for the final rendering was cloned and moved across the scene for have several frames of the object, which has the described artifacts. Further, using the scripts, which were actually made for other purposes, created one additional camera and its position was animated. This camera exactly repeated the position the primary and secondary cameras with each new animation frame. The result came out something like fly-through animation, in which the camera flied round the problem objects. Next, were rendered the primary and secondary GI bounces maps for each frame of animation, and simultaneously merged into two maps that are general for each type of bounces. Thus, more detailed and dense GI maps were obtained. After that, these maps were used for the calculation of the only final frame from the first original camera view.

Of course, such specific approaches may eliminate in some sense the problems with the GI, but they are just boring in their implementation and they take the lion's share of the scene setup time, while being inelegant and hasty solutions. It makes no sense to bore ourselves with agonizing adjustment and experimentation for each new scene, achieving a desired result. Understanding the essence of the problem, it is very elementary to fix such problems at similar or even lower computing time cost.

To realize the nature of the problem, we should return to the principle of IM. In particular, to its way of probing the geometry of the scene at lower resolutions. In most cases, as well as in the universal starting V-Ray configuration, undersampling is used even in the final IM prepass. That is, the color samples of IM are taken from a much lower resolution than the final one. After that, they are interpolated to the desired resolution, while also filling not sampled areas. In the example above, both images were rendered at a resolution of 400 by 500 pixels. The left image was calculated with the value of Max rate equal to -4. This means that the final prepass of IM was made in 400 by 500 resolution, divided by 2, divided by 2, divided by 2 and again divided by 2. That is, in the resolution of 25 by 31 pixels.

Here is the same render, calculated in 25x31 pixels and then interpolated in Photoshop up to 400x500 pixels.

low resolution irradiance map interpolation to final rendering resolution
This image repsenets how little can the irradiance map may be and to which sizes it can be interpolated. Certainly, the level of details on the obtained this way map is out of the question here.

Gray rectangle to the left is not interpolated render in the resolution of 25x31 pixels. Even with very high values of the interpolation and information about the geometry of the scene, get the small details from such low resolution is simply unrealistic. If two or even three white partitions of our grid at a resolution of 25x31, are marked with one black pixel, and the dark spaces between them all, for example, with one white, then no matter how we interpolate these pixels, after the interpolation they any way will look like blurry smudges. These spots produce those mentioned flakes on the fine details of the scene.

Now you surely understand that to obtain detailed IM and get rid of the stains in the corners, we need to increase the resolution of the last IM prepass. This was done in the previous example in the image on the right. IM was calculated with Max rate equal to 0, i.e., the final rendering resolution. The right example has no visible artifacts as well it has much more clearly visible shadows, which not blurred by low-resolution irradiance map interpolation.

If only some objects of the scene have this like artifacts, there is no need to calculate the entire frame with a more detailed IM. It will unreasonably take many hours of calculations, giving essentially the same results on all other non-problematic scene areas. In order not to consume computing resources vainly, we rather use the Region render and calculate only those parts of the image, where the quality is not good enough.

Conclusion

The approach to the GI setup described in this and three previous tutorials is the most efficient from a practical point of view. Do not waste for nothing your time, money and electric power, spending them on the hit-and-miss methods ;)

Dear friends, we sincerely hope that carefully reading these tutorials, you have clearly learned the essence of indirect lighting, you are now free in its settings and ready to easily apply your knowledge in practice for obtaining great visuals!

In the following tutorials we will learn about V-Ray speed and quality control, and also will go deep into renderer's system settings.

All have easy settings and beautiful 3d renderings!



19 Feb, 2011 Joc
19 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Again, simple and clear. 3 thumbs up!
It's obvious that in any CG image, illumination is the "unf" factor that brings one's work to life.
As a humble CG artist (since the days of 3D Studio - anyone still remebers it?), I must say that I learned a lot, in terms of understanding how vray does the job and how to make my workflow more efficient.
Those 4 tutorials are simply and plainly excellently written and are must to read.
What would be my wish? I think the next step in the creation process would be the DMC and all the implications and correlations it has on materials, light, final quality, etc..
Anyway, thanks for sharing your knowledge and making me a smarter man.

Cheers till next time.

Joc

19 Feb, 2011 RenderStuff (Staff Author)
19 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
The next tutorial will exactly describe the Settings tab, including the general quality/speed consideration, the most often RAM issues, and how to efficiently manage V-Ray settings. We actually even made the thumbnail and vray-engine banner for that tut 🙂 But its writing will take a time.

Thank you for your interest! We truly glad that we reached our reader.

19 Feb, 2011 Maksvel
19 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Cool, all in great detail! I understand that in the next lesson we will focus on settings tab, and then there will be lessons on VRayMtl and VRayLight? Another would like to learn about the specifics of the rendering of the animation.


19 Feb, 2011 RenderStuff (Staff Author)
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Hello, Maksvel. You surely guess. Next lesson for optimal settings V-Ray will describe the Settings tab. In particular, the global parameters DMC Sampler, allowing to find a compromise between quality and rendering speed; the correct management of RAM allocated to the rendering of the scene, and several major utilities. Regarding future lessons on other subjects, we write, and write them, affecting various aspects of computer graphics, including photorealistic rendering and animation statics, materials and lighting. This, of course, takes a lot of time and, unfortunately, can not do anything specific about the timing of their release, we say, except that they are coming 🙂 For the traceability of all new products, subscribe to updates of the site and you will be informed of all the news!


20 Feb, 2011 Rookie
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
I read all of the lessons, all very nice and clear, but in practice it turns out no-taki as lesson 🙂 I had a following problem - to those "unimportant" areas iradians mapy that greyish, is noise, no stains and no wool and a small, small noise, improve probyval samples interpolation to smooth out the noise, but that is not particularly helpful. Prepass also increased, but did not help. The scene is not complicated, how about you 🙂 I can throw the picture, but do not know where, and I also have interesting information on the methods of sampling addaptivnyh why it is sometimes better to use adaptive DMC, rather than adaptive subdivision. In general I liked the article, one can see that people understand, count on your help! 🙂


20 Feb, 2011 Hudruk
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Thanks again, all laid out on shelves, it remains only to try and experiment. The specifics of this that often come across the room without windows, is now very interested in setting light. Will be in the future?


19 Feb, 2011 RenderStuff (Staff Author)
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Hey, Rookie. It could be anything, and probably not even connected to the IM in principle. Do not forget that the result affects the geometry of the scene, applied materials, lights and render direct illumination settings, etc. Upload images to any Image Hosting , and throw off here a direct link to it, and be sure to screenshots of all the settings - will understand what was going on 🙂


19 Feb, 2011 RenderStuff (Staff Author)
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Artistic director, yes definitely. There is a detailed tutorial for the visualization of the interior, and later - and exterior. As for the timing - as mentioned above in the comments 🙂


20 Feb, 2011 Rookie
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Now tune the general lighting, places like that do not are marked with "-", like a "+" do not like total grain http://s009.radikal.ru/i310/1102/54/87a3f89d66c0.jpg


19 Feb, 2011 RenderStuff (Staff Author)
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Rookie of the, in the settings values are shown to you at least eleven parameters, such as the Image sampler, Sub-pixel mapping, Clamp output, LC subdivs, Sample size, Adaptive tracing, Store direct light, Use light cache for glossy rays, IM Clr thresh, Dist thresh, Detail enhancement displayed incorrectly. Their values ​​do not match the values ​​recommended in the lessons. To expose the settings by following the lessons in values ​​to achieve a good result.


20 Feb, 2011 Hudruk
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Hello, RenderStuff. Here, as promised I spread his creation on the basis of your lesson. The main problem, slurred and faded visualization. 1. a visa turned; 2. Vray settings; 3. The general screen of the scene; Thank you 🙂 Hello, Rookie. Good luck to you in 3D-shnom difficult matter 🙂 Tell me how to link to this image to make the active?


20 Feb, 2011 Rookie
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
I put on the night of the settings exactly in exactly with yours, see what happens tomorrow necessarily lay Hi, artistic director! Same to you 🙂 I'm not the highlight, is modernizing tried. Yes, and wish for your wonderful resource online very much lacking! 🙂


19 Feb, 2011 RenderStuff (Staff Author)
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Artistic director, of course, to expose Light cache settings, as described in the previous lesson. As described, Store direct light function can not be used for photorealistic rendering in order to avoid non-natural distribution of direct light. Also, Pre-filter with a value of 50 greatly dilutes the shadows. PS: The main problem is not realistic installation of light sources. Just great, do not exist in the real world, light sources, such as in your scene on the ceiling, nullify all the light composition, too vybelivaya interior.


20 Feb, 2011 Hudruk
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
I created them (huge light sources), for general light and to illuminate the ceiling. There were two options for visualization, with photometric lights and conventional VrayLight (the one that sent). For comments thank necessarily correct, and lay out. But as I understand, the special weather, they do not have to change the light?


19 Feb, 2011 RenderStuff (Staff Author)
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Talk correct installation of light beyond the scope of this tutorial. Configuring filtering still help to make a few more contrasting shadows, however, as you guess GI change the settings in this situation, unfortunately, is not particularly affect the result😉


20 Feb, 2011 Hudruk
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
In any case, thank you very much for your hard work and a desire to help. How do we talk to the account of the world? Support your site will be able to help with this? 🙂


19 Feb, 2011 RenderStuff (Staff Author)
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
🙂 Please support resources will definitely help the exit follow the lessons, including on setting up the lighting, based on which we can talk😉


20 Feb, 2011 Hudruk
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Hello again) Light cache settings changed in the lesson function disabled Store direct light, Pre-filter set 10. Here is the result. BUT, there was a noise in the tower and the podium, if within the lesson, tell me how to fight? Something tells me that it is light again 🤔


19 Feb, 2011 RenderStuff (Staff Author)
20 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Hello 🙂 No doubt, rendering became more realistic shadows appeared. Selected problem areas and present you the last time, but were stronger lit and not so noticeable. But, again, it is rather a problem of the quality settings of direct light and transparent materials 🙂


20 Feb, 2011 Hudruk
21 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Help ((((Well can read where it is possible? (I'm all about light and materials).


19 Feb, 2011 RenderStuff (Staff Author)
21 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Artistic director, we can do you currently offer to send us an email (see contact ) link to the file to your scene. Only then, when he saw all of its details, not only on screen, we can give you specific advice. Of course in personal correspondence, not to raise offtopic comments to this lesson 🙂


21 Feb, 2011 xt13r
21 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Thanks for a such full and exhaustively tutors!
i'm looking forward for the next tutor)

20 Feb, 2011 Hudruk
22 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Hello, RenderStuff 🙂 Thanks for the offer, the file sent.


22 Feb, 2011 Singlebit
22 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Lessons are the best on the Internet! Thank you so much! I would recommend to friends.


23 Feb, 2011 Ivan
23 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Hello, RenderStuff 🙂 Very informative lessons, thank you very much for them 🙂 I noticed that in your lessons you always emphasize the universality of Vray settings, hence the settings for the final rendering are essential differences? Are you planning to introduce its readers and subscribers with them? In addition, very interested in how you set up the light in his work, relying on what parameters? interiors, exteriors? With all the flexibility of the light settings in the Vray twist these same settings can be a long, assessing eye results and gradually achieve the desired, but it is much faster than it would take some some element in the scene, the conventional "reference point" of all the other parameters, whether the sources of illumination, setting cameras or color mapping. Personally, I would be very interested to know your experience in this respect 🙂


19 Feb, 2011 RenderStuff (Staff Author)
23 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Hello, Ivan. We are glad that you are helping to publication RenderStuff. Yes, as described in this series of lessons tweaks are just starting to universal settings. This means that, starting its visualization scene is with them, you are proactively get rid of most of the problems and getting a good balanced result. This does not mean that these settings should be changed to the final rendering. Not at all. Make adjustments to them is only in those cases when there are any visible artifacts in the scene. Only then should modify the settings to remove them. The essence of the universality of the settings described in the first lesson - on Antialiasing and Color mapping in chapter Start-Ray setting the V . Which settings should be changed in any way? Here it depends on the specific situation. To that end, the lesson contains comprehensive information on each of them, and it discusses the most common problems and their solutions. Read, heed and act 🙂 Ivan, on the lessons of the interior and exterior lighting, carefully read the comments on the lesson, in which you are sure to find the answer to your question.


23 Feb, 2011 Ivan
23 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
thanks for the reply 🙂 looking forward to following your publications


25 Feb, 2011 Elza
25 Feb, 2011 # Re: GI Engines VRay 1.5 tutorial
Thank you for the lessons very interesting and simple! but I connected the v-ray sun and sky turns overexposure. How do I adjust the lighting? Reduce the setting of the sun, or something else?


19 Feb, 2011 RenderStuff (Staff Author)
2 Mar, 2011 # Re: GI Engines VRay 1.5 tutorial
Elza, hello. Read the comments on this article: http://renderstuff.com/vraysky-colorcorrect-tutorial-46/ 😉


8 Mar, 2011 Bob
8 Mar, 2011 # Re: GI Engines VRay 1.5 tutorial
Just great!

22 Mar, 2011 maksvel
22 Mar, 2011 # Re: GI Engines VRay 1.5 tutorial
Taki where continuation? I look forward to.


24 Mar, 2011 Alex
24 Mar, 2011 # Re: GI Engines VRay 1.5 tutorial
Good evening, RenderStuff, I have you next question: everything is done according to your lessons and before the final closing renderer appears some prepass where all black, are just some of the objects can be seen and then some gray, is it ok and iz which is why you may receive this prepass ... just when rendering the individual elements do not exist, and when the whole scene together is processed, it appears. Thanks in advance! The lessons you have excellent, looking forward sledushchego!)


19 Feb, 2011 RenderStuff (Staff Author)
24 Mar, 2011 # Re: GI Engines VRay 1.5 tutorial
VRayMtl materials can be used for the interpolation algorithm IM glossy effects, if the material is ticked Use interpolation. Scrolls Reflect interpolation and Refract interpolation, just allow you to specify the number of prepass to calculate interpolation glossy effect. If Reflect and Refract interpolation, values ​​Min and Max rate different from the values ​​set out in the IM, it can boost the appearance of additional prepass interpolation for glossy effects of this material. For example, since proizvoydet if IM settings Min rate, -5 Max rate -2, Reflect interpolation and one of the materials in the scene Min rate -6 Max rate -1. This setting will cause the appearance of two additional prepass, which will be used for the interpolation calculation only objects with this material, but they will not be involved in the GI rendering for the entire scene. That's why you see this prepass black, and those mats, for which it is calculated - you see gray. Even in a situation of non-use of IM in general, the inclusion of the above settings for any scene materials, will be familiar prepass IM, intended only for the calculation of interpolation glossy effects.


24 Mar, 2011 Alex
24 Mar, 2011 # Re: GI Engines VRay 1.5 tutorial
Thank you very much for the answer)


27 Mar, 2011 Provisuals
27 Mar, 2011 # Re: GI Engines VRay 1.5 tutorial
What an excellent set of tutorials. It as helped me to understand the Vray Parameters a lot better and without being intimidated by them.
Looking forward to your next Tutorial. Thanks

5 Apr, 2011 LORD
5 Apr, 2011 # Re: GI Engines VRay 1.5 tutorial
And when is the next lesson? 🙂🙂


19 Feb, 2011 RenderStuff (Staff Author)
5 Apr, 2011 # Re: GI Engines VRay 1.5 tutorial

15 Apr, 2011 vishal
15 Apr, 2011 # Re: GI Engines VRay 1.5 tutorial
what is a primary bounces and secondary bounces

19 Feb, 2011 RenderStuff (Staff Author)
15 Apr, 2011 # Re: GI Engines VRay 1.5 tutorial
Vishal, to know about the theory of Indirect illumination and, in particular, about primary and secondary bounces, read the global illumination in computer graphics.

17 Apr, 2011 a-kit
17 Apr, 2011 # Re: GI Engines VRay 1.5 tutorial
RenderStuff: The issue moved to the appropriate section of the discussions on the correct setting of interior lighting in-Ray the V .


25 Apr, 2011 DoD
25 Apr, 2011 # Re: GI Engines VRay 1.5 tutorial
Thank you all very detailed! I have a question in network rendering LC Number of passes to insert a value ???


19 Feb, 2011 RenderStuff (Staff Author)
25 Apr, 2011 # Re: GI Engines VRay 1.5 tutorial
Hello, the DoD, about what value LC Number of passes necessary to expose, described in detail in a previous article on the work of the Cache Light . All described there is true for network rendering. In particular, because unfortunately, LC is not distributed to all computers involved in grid computing and considered anew from scratch each. In any case, more on that you read it in a lesson😉


25 Apr, 2011 DoD
27 Apr, 2011 # Re: GI Engines VRay 1.5 tutorial
Ewe raz spasiba za uroki, oni klasniye! Hochu sprosit pomoyemu vse versiy vraya otlechayutsa drug-otdruga kakuyu versiyu vi mojete rekomendavat, imenno po bistrote vi4esleniyam ?. Umenya sey4as stoit max 2011 & vray 2.0 no ranwe max 2009 design & vray 1.50 sp2 i bistreye rabotal.


19 Feb, 2011 RenderStuff (Staff Author)
27 Apr, 2011 # Re: GI Engines VRay 1.5 tutorial

4 Jul, 2011 Andrey
4 Jul, 2011 # Re: GI Engines VRay 1.5 tutorial
Please tell me that's about this phrase:
In most cases, as well as in the universal starting settings V-Ray, undersampling is used even in the final resolution rendering IM. That is, the color samples are taken IM a much lower resolution than the final. Thereafter, they are interpolated to the required resolution, while still filling up the missing region.
namely -tsvetovye IM samples are taken with a much smaller razresheniya- ie if I ask permission to certain, then why is it considered to be a much smaller ?? what's the point if the programmer put his permission? I apologize if you really tuplyu =)


19 Feb, 2011 RenderStuff (Staff Author)
6 Jul, 2011 # Re: GI Engines VRay 1.5 tutorial
Hello! You just need to understand the concept of sampling. In particular, what supersampling and what undersampling. In order to understand what it is, just carefully read the first lesson about the V-Ray the Antialiasing . Particular attention should be paid to you in the chapter dedicated to the V-Ray Image sampler rollout (the Antialiasing) , which describes the work of this algorithm, and in particular the principles of AA . There are detailed technique of undersampling and supersampling.


4 Jul, 2011 Andrey
30 Jul, 2011 # Re: GI Engines VRay 1.5 tutorial
Thank you, RenderStuff, read, such as understanding comes! =)


4 Jul, 2011 Andrey
30 Jul, 2011 # Re: GI Engines VRay 1.5 tutorial
C it seems to be understood, but then please tell me, in which case then you just need to raise the value HSph.subdivs and in which interp.samples &


19 Feb, 2011 RenderStuff (Staff Author)
31 Jul, 2011 # Re: GI Engines VRay 1.5 tutorial
Hello! HSPH. subdivs a setting that should always raise if it enables computation RESOURCES your computer. The worst of it is not. The bigger, the better. What matters is that the rendering time is gone "to infinity"😁 The more value HSph. subdivs, the cleaner will map Irradiance Map. There will be more detailed and less noisy. Usually, in practice, the values ​​in the area of ​​80 - 120 subdivs would be sufficient. Parameter Interp. Samples, conversely, the lower the value, the less blurred and more detailed map IM. To increase its worth only in those cases when you have, for whatever reason, the value HSph. subdivs - very low and Irradiance Map is simply not enough information to form a beautiful GI card. This is manifested in the form of noise and dirty spots. Increasing Interp. Samples, you are stronger razmoesh IM and thus get rid of a little noise. However, as you would expect from a blur, all the little details, which include the noise itself, this will be blurred blur. So you get a blurry picture is fuzzy. For photorealistic rendering it is always important to keep HSph. subdivs and low value Interp. Samples. This will not get noisy, but it is highly detailed visualization clear. The only thing is to adhere to, is the fact that the Interp. Samples less than 20, will do IM noisy even at high HSph. subdivs😉


4 Jul, 2011 Andrey
7 Aug, 2011 # Re: GI Engines VRay 1.5 tutorial
Many thanks ! It exhaustively explained =)


8 Aug, 2011 ASRockus
8 Aug, 2011 # Re: GI Engines VRay 1.5 tutorial
You say that
Parameter Interp. Samples less than the less blurred and more detailed map of IM
. And write in conclusion:
The only thing is to adhere to, is the fact that the Interp. Samples less than 20, will do IM noisy even at high HSph. subdivs
. Then how can it be? To put a fixed value and always adhere only to that figure? Prokomentirujte please.


8 Aug, 2011 Anton (Staff Author)
8 Aug, 2011 # Re: GI Engines VRay 1.5 tutorial
Hello! Yes exactly. In any case, the recommended settings for IM read in the article about the optimal settings the Map the Irradiance . There's all the recommendations set out in a completely unambiguous manner, without ambiguity. You should adhere to them)


9 Sep, 2011 Aleksandr III
9 Sep, 2011 # Re: GI Engines VRay 1.5 tutorial
Put please screens with all the correct settings, if that is possible more virey camera. I will be very grateful.


8 Aug, 2011 Anton (Staff Author)
9 Sep, 2011 # Re: GI Engines VRay 1.5 tutorial

Thank you for your interest.

That's what we plan to do, and in the final part of a series of articles about the optimal settings V-Ray. And also tell you how to use presets, set the following settings for default scene 3ds Max and manage the priority of the rendering process.

This will be through the article. That is very soon.

Regarding the camera, see lesson replacing the VRayPhysicalCamera . It describes the main "Settings" virey fizikl camera😉



5 Jan, 2012 Nikolas
5 Jan, 2012 # Re: GI Engines VRay 1.5 tutorial
Good afternoon, RenderStuff! For the second day of fighting unsuccessfully with "wool" on furniture and moldings. It seems to be setting in lessons uvelichval number of passes, leaving only the v-ray sky, at about 24 subdivs materials and more. Tulle removed, the noise has become smaller, but not much. So I hope for you 🙂 Thanks in advance! Settings: render: IM:


8 Aug, 2011 Anton (Staff Author)
5 Jan, 2012 # Re: GI Engines VRay 1.5 tutorial
Hello! The main "culprit" of the problem, can easily be bright VRayLightMtl ceiling (zakarniznaya lights). Try to start with, it is to disable it, and only if it does not help to start to turn the other settings. This kind of dirt on the rendering, not always from the GI, it may be an artifact of the very shadow of the light source. Usually it occurs when something interferes with the passage of the direct rays of light directly from a light source. For example, blind or glass before the Light. Or the same light source setting too low. For example, if you use light in the skylight portal mode, the number of sabdivs be too high to keep it. In the area of ​​60 - 90 Subdivs. Make sure that nothing does not interfere with the passage of rays of Light, as well as the number of Subdivs in its settings is sufficient to generate soft shadows gradients. Just do not be pererenderivat entire image during the experiments. It is enough to render the region and, in the "dirty" place to tweak all the settings required to😉


5 Jan, 2012 Nikolas
6 Jan, 2012 # Re: GI Engines VRay 1.5 tutorial
Thank you for your prompt response! >> The main "culprit" of the problem, can easily be bright VRayLightMtl ceiling (zakarniznaya lights). Disabling Lite on the noise level did not affect the value of the brightness in the material 5. >> Try to start with, is to disable it, and only if it does not help to start to turn the other settings. >> This kind of dirt on the rendering, not always from the GI, it may be an artifact of the very shadow of the light source. >> Usually occurs when something interferes with the passage of the direct rays of light directly from a light source. >> For example, blind or glass before the Light. If you disable and blind, and Plain with the backdrop, the noise disappears. >> Or the same light source setting too low. >> For instance, if you use light in the skylight portal mode, the number of sabdivs be too high to keep it. In the area of ​​60 - 90 Subdivs. Included portal with the specified settings, and the noise is almost gone! >> Make sure that nothing does not interfere with the passage of rays of Light, as well as the number of Subdivs in its settings is sufficient to generate soft shadows gradients. Strange, but if I unplug the cast shadows from the curtains and cast shadows and visible to GI in the backdrop, the noise does not disappear. Apparently you need to disable some other settings? >> Do not be pererenderivat entire image during the experiments. It is enough to render the region and, in the "dirty" place to tweak all the settings required to do so became, thanks! 🙂


8 Aug, 2011 Anton (Staff Author)
6 Jan, 2012 # Re: GI Engines VRay 1.5 tutorial

I advise you to read the discussion about the acceleration of render , in the future, with the placement of lights o windows with curtains - to act as it is written there.

Then there is nothing out of nothing will not have to exclude the rendering will be faster and cleaner😉



5 Jan, 2012 Nikolas
6 Jan, 2012 # Re: GI Engines VRay 1.5 tutorial
Anton (RenderStuff), once again thank you for finding help 👍 time I understand correctly, that disabled skylight portals renders must make a noise?


8 Aug, 2011 Anton (Staff Author)
6 Jan, 2012 # Re: GI Engines VRay 1.5 tutorial
Nikolas, highly abstract question. No specific context it is not clear and can be interpreted in different ways. In any case, it is beyond the scope of this discussion. Ask it more specifically, in an appropriate subject, or create a new one.


5 Feb, 2012 Aleksandr
5 Feb, 2012 # Re: GI Engines VRay 1.5 tutorial
Sorry =🙂 We see something, or A4 pererenderit?


8 Aug, 2011 Anton (Staff Author)
5 Feb, 2012 # Re: GI Engines VRay 1.5 tutorial

With the cornice, everything is in order. I see, only, tiny light gray spots in its lower part. But only if you specifically look there.

This is quite an acceptable result, as for a small object with white material that is out of range of direct rays from the light source.

If you have a purely matter of principle, then put IM min -6 max 0 or even max 1, HSph. Subdivs 120 subdivs. Also do not forget to rotate the subdivs at the light source, under 120. At the same time, and LC turn under 3500 subdivs. And wait ...

But it's not worth it.

It should be understood that this cornice is illuminated only by secondary beams GI, reflected from the wall, opposite the window. This is the most difficult area for the lighting of the stage. It's no wonder that even with high GI settings, artifacts are visible on it.

The most "whimsical" material, from the point of view of the prominence of artifacts on it, is just material, with just the color of Diffuse instead of the texture on it. And the most "whimsical" diffuse color is white. And at the end, the smaller the object itself, the harder it is to render the engine based on interpolation, as IM does.

In the end, you get the most difficult situation with this cornice, as it, in fact, will count the most "whimsical" attributes.

The best solution in this situation is to eliminate these micro-spots on the cornice, using post-processing in Photoshop.

It's now a small empty room, but if it's a big scene with a bunch of objects, and you try, just for the sake of these specks on the cornice, to lift the GI settings to the level described above, then your render can and will be more beautiful and cleaner, but its time "Will go to infinity".

And all this for the sake of removing a couple of spots on the cornice, which is hardly worth doing 🙂

Do not fool yourself with a head😉



5 Feb, 2012 Aleksandr
5 Feb, 2012 # Re: GI Engines VRay 1.5 tutorial
Thank you =🙂 Just in the resolution of the A4, they are quite noticeable. But if overrayd to turn white at the scene, the wool is not at all. Probably because the illumination by white becomes greater.


7 Feb, 2012 Peps
7 Feb, 2012 # Re: GI Engines VRay 1.5 tutorial

11 May, 2012 Marcos de Oliveira
11 May, 2012 # Re: GI Engines VRay 1.5 tutorial
🙄 How can I avoid artifacts in animated objects using VRay? Even rendering frame-by-frame, the objects changes it colors, causing a strange effect. Please help, thanks.

24 Jan, 2013 Ioan Alex
24 Jan, 2013 # Re: GI Engines VRay 1.5 tutorial
TY!!
Yes, I am a human 😁

8 Nov, 2013 Nikolay
8 Nov, 2013 # Re: GI Engines VRay 1.5 tutorial
Good afternoon. Help please, to address the following issues, I have the render on the baseboard appears "dirty", the problem can be solved by exhibiting high parameters (Irradiance Map), (Adaptive amount), (Noise threshold) and (Global subdivs multiplier), but dramatically increases render time. Material used VRayMTL all other settings are the default material. Can I remove the "dirt" by adjusting the material, because the material on which the applied raster maps "dirt" does not appear? And please tell me how to set up the material -Colors or enamel. Thank you.


8 Nov, 2013 gus_ann (3dsmax vray expert)
8 Nov, 2013 # Re: GI Engines VRay 1.5 tutorial
Nicholas, you yourself answered his first question-or an increase in the use of options or card material vie yard Dirt. This is the lesson. As for the material of paint or enamel, it's up to you here. What is your idea on a plinth made of? From wood and painted? Then paint. Maybe it plastic? So it is necessary to make the plastic material. 😉


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