Sự phát triển của VRay đã được bắt đầu hơn mười năm trước đây, phương pháp Brute Force (thuật toán số dương) nói chung quá chậm để tính toán. Phương pháp nội suy nhanh như Irradiance Map và bản đồ Light Cache được phát triển, và kết quả là VRay chưa bao giờ đặc biệt là tối ưu hóa cho Brute Force. Các phương tính toán ưu tiên cũng có tác dụng phụ trong việc thể hiện chi tiết của vật thể và dễ bị nhấp nháy khi làm phim. Và với phần cứng hiện nay cộng với tiến bộ trong các thuật toán, brute force bây giờ là một lựa chọn khả thi hơn. Chaos Group đã dành thời gian tối ưu hóa Brute Force ở phiên bản này bằng cách thêm hỗ trợ cho các Embree raycaster (có sẵn khi vẽ trên bộ xử lý Intel).
Trang 1V-RAY 3.0 AND
APPLIED PHOTOGRAPHY
E-book about news in V-Ray 3.0 applied to the book
Photography & Rendering with V-Ray
Trang 2Copyright © 2014 by GC edizioni
all rights reserved
GC edizioni
Corso America, 57
09032 Assemini (CA)
Ph and fax 070-8809018
www.gcedizioni.it libri@gcedizioni.it Author
Ciro Sannino
Publishing, Graphics and Layout
Gabriele Congiu
Editing and Revision
Barbara Sulis
Translation
Johanna Worton
E-book completed in July 2014
The authors and publisher accept no liability for damages of any type arising from the improper use of the program All brands cited herein have been registered by their respective producers, particularly Autodesk and 3ds Max, which are Autodesk registered trademarks; V-Ray has been registered by Chaos Group All rights reserved No part of this manual can be reproduced, translated, copied or transmitted in any form or by any means,
without the publisher’s prior written consent
Trang 3V-Ray 3.0 and
Applied Photography
Introduction 4
Gamma Compensation 4
The Render Pannel 7
Progressive & Render Mask 8
Exercise: How to take advantage of the Render Mask 10
V-Ray Frame Buffer 12
V-Ray Toolbar and V-Ray Quick Settings 14
Production time 16
Personal vision 16
Order your copy now 17
Learn V-Ray 17
Trang 4V-Ray 3.0 and
Applied Photography
The book“ Photography & Rendering with V-Ray ”
focuses entirely on the implementation of basic
photographic concepts in the process of creating an
image through rendering.
The various examples in the book refer to version
2.0 of V-Ray, but a user with version 1.5 can also
use it very easily.
The same goes for anyone who has updated to
version 3.0 On the photographic level basically
nothing has changed, as this would be absurd
However, seeing as several commands now have
different names, or are simply found in different
places, I have written this e-book so that using the
main book is even easier.
Trang 5Figure VR3-2
Until version 2013 of 3ds Max the gamma compensation in input and output could be changed using the “Bitmap files”
box in the Gamma and LUT tab
Figure VR3-1
From version 2014 “Input
and Output Gamma” are
managed automatically
and the “Bitmap files”
box has been removed
Introduction
After little over a year V-Ray 2.0 took a new leap forward and launched version 3.0 at the
beginning of 2014 It contains various additional features that contribute to making the
production process simpler and more logical Many improvements concern the core of
the software and are related to increasing performance Several new options have also been introduced, none of which, however, change the photographic rationale behind
Photography & Rendering with V-Ray This could not be otherwise, as photorealism means first of all adopting a photographic attitude, which automatically produces a photographically correct result
A detailed overview of all the new features is available on the official website
http://www.v-ray.com In this e-book we are going to look at the V-Ray 3.0 updates that are good to know
so that you can always find everything you need to implement photographic concepts using V-Ray
Gamma Compensation
Compensation using the gamma curve is extensively described in Chapter 2 - Compensation
Using the Gamma Curve of Photography & Rendering with V-Ray, from both a theoretical and photographic point of view and is accompanied by practical exercises The explanation
of gamma compensation is universal and naturally always valid, not just for V-Ray, but for
any other software dedicated to photorealism
Its implementation has become much simpler in the versions 3ds Max 2014 and V-Ray 3.0
Everything stems from the fact that in 3ds Max 2014 management of the gamma in Input
(texture) and Output (render) is automatic The Gamma in preferences is already set to a
value of 2.2 and cannot be changed, Figure VR3-1 This is different from in previous versions,
in which it was necessary to set the gamma manually, Figure VR3-2
Trang 6E-book: V-RAY 3.0 NEW FEATURES
Considerations:The Gamma Input and Output can actually be changed by using a line
of max script However, I’ve noticed that, unless you know the whole theory well, it’s
always better to use the default settings of 3ds Max, without changing them Nor is
it inconceivable that sooner or later the “Bitmap files” box could return So the most
important thing is to always be completely aware of why certain procedures are carried
out, as clearly explained in Chapter 2 of Photography & Rendering with V-Ray.
Figure VR3-3
The “Enable built-in frame buffer” option, which allows you to produce the rendering
in the V-Ray Frame buffer, is highlighted
Figure VR3-4
The option used to show a preview of a render compensated using the gamma curve
Figure VR3-5
In the Color mapping rollout the
“Gamma” has already been set
to 2.2 and the “Mode” to “Color Mapping only (no gamma)”
Figure VR3-6
The recommended option for gamma when saving is
“Automatic”
CONTENTS
5
For this reason Chaos Group has seized the opportunity and, as far as the gamma issue is
concerned, has made it so that V-Ray 3.0 is perfectly integrated with 3ds Max by default In
the following images - Figure VR3-3, Figure VR3-4, Figure VR3-5 and Figure VR3-6 - let’s look
at how V-Ray 3.0 now appears upon opening.
Trang 7Notes: In Chapter 2 of the book the “classic” combination is used to obtain the correct
Gamma compensation This involves setting the gamma output in the preferences to 1.0
The result is, however, the same
Considerations:At first glance, having many ways to do the same thing automatically leads up to think that one way is better or at least more advisable than the others I
personally suggest using the default settings of V-Ray 3.0 and 3ds Max 2014 when you
start a project from scratch, and continuing to use the so-called “classic” setting, with the gamma output set to 1.0, if you find this type of configuration when you open an old file It is simply a question of convenience
Coordinated in this way, the two systems, V-Ray 3.0 and 3ds Max 2014, already produce
and save correctly compensated images, using the gamma curve by default for any output format used
If you have 3ds Max 2014 (which no longer allows you to change the gamma in preferences), but haven’t yet purchased the V-Ray 3.0 upgrade, you can simply manually set the same configuration that V-Ray 3.0 adopts as a default.
Let’s sum up the options that have changed slightly and which are shown in Figure VR3-3,
Figure VR3-4, Figure VR3-5 and Figure VR3-6 on the previous page:
1 Activating the V-Ray Frame Buffer, Figure VR3-3;
2 Enabling the gamma preview using the sRGB button in the V-Ray Frame Buffer, Figure VR3-4;
3 Setting Color Mapping to 2.2 and selecting the “Don’t Affect Colors” checkbox (option no
longer exists under this name in V-Ray 3), Figure VR3-5;
4 Ensuring that saving occurs with the Automatic option enabled, Figure VR3-6 Remember that whichever method you use to obtain correct compensation, the result
will be the same When working with 3ds Max 2014 (or later) together with V-Ray 3.0, we
suggest you begin your new projects without changing the already perfect default settings
Trang 8E-book: V-RAY 3.0 NEW FEATURES
Figure VR3-7 On the left, the Render Setup panel that has always accompanied the developments of V-Ray since
its inception The new, more practical and more compact Render Setup panel is shown on the right.
Figure VR3-8 In the Render Setup panel on the left “Adaptive DMC” antialiasing is highlighted In version 3.0
this has become “Adaptive” The new “Progressive” option can also be seen in the drop-down menu.
CONTENTS
The Render Panel
The interface of the Render Setup panel, Figure VR3-7, (which can be activated using the
classic function key F10), may appear completely different at first Three buttons, called
Basic, Advanced and Expert, have simply been added By choosing one of them, you can
hide more or fewer options If you enable Expert in all the rollouts (where possible), V-Ray
appears almost identical to the previous version Here are a few small changes that are
worth highlighting, in order
The “Render Setup” panel is basically the same - it is just narrower:
Adaptive DMC antialiasing is now simply called Adaptive, Figure VR3-8 It has just changed
its name and is still set as explained on page 172 of the book, in which we talk about step-4
of the 5SRW method, dedicated to the production of sharp, clean images
7
Trang 9Notes: The Noise Threshold parameter has changed positions While previously it could
be found in the SETTINGS section of the rendering panel (F10), it is now in the V-RAY section of the “Global DMC” rollout Its function, however, has not changed
Figure VR3-9
The Reinhard and Burn value options highlighted
Figure VR3-10
The Progressive option and the relative field in which to set the render time are shown
For years the default system in the Color Mapping rollout has always been Linear
Now the default Color Mapping is Reinhard,with the Burn value option set to a value of
1.0, Figure VR3-9 As explained in the book, this is actually the exact equivalent of Linear Officially the default setting has not changed but with Reinhard, V-Ray can more easily
manage the highlights
For an accurate explanation of how and when to use the three main color mapping methods
(Linear, Exponential and Reinhard), refer to the book from page 99 onwards.
Progressive & Render Mask
Several very interesting new features can be found in the Image sampler (Antialiasing)
rollout, including the Progressive and Render Mask options, Figure VR3-10 These two new production tools make your work easier and significantly affect finishing and delivery times Let’s start with Progressive antialiasing This allows the final render to be produced, no
longer using buckets, but as a whole image This image is initially very grainy but becomes
cleaner and cleaner as minutes pass
It is a similar technology to V-Ray RT The latter, however, implements all the functions and
also depends on Irradiance Map and Light Cache for Global Illumination It’s a very convenient
type of production, particularly when you don’t have a lot of time available
Trang 10E-book: V-RAY 3.0 NEW FEATURES
Considerations:In Figure VR3-11 you can see an image I made during the beta phase of
V-Ray 3.0 to test Progressive This has become the testimonial image of the Progressive
function and you can also find it on the official website www.v-ray.com
Figure VR3-11 Screenshot of the rendering after just 3 minutes of processing You can see a
lot of grain, which disappears as Progressive continues its calculation.
CONTENTS
9
The image in Figure VR3-11 is a screenshot taken during processing Here is some information
related to the process:
• Image width 1200px;
• Irradiance map: high / Light Cache: 2000
After the first 5-6 minutes calculating the Global illumination with Irradiance Map and Light
Cache the render began in Progressive mode The image in Figure VR3-11 is the result after
just 3 minutes of processing
The speed when using the Progressive option is more or less the same, but the way the
render is produced is different This new type of antialiasing does most of the work in the
first few minutes and then takes all the time needed to reach a high level of definition So we
can let it process until we are satisfied or for as much time as we have available
For this reason Progressive really is an intelligent solution for flexibly producing renders
Progressive allows you to have a finished render available at any time It may be grainy, but
it will, however, be a complete render
In the Render Time field we can set the processing duration or simply set the time to 0,
which corresponds to infinity, so the render will continue indefinitely and we can stop it
when necessary
Trang 11Figure VR3-12
The image is obtained
in just a few minutes, showing the chair with opaque reflections
Figure VR3-13
The Render Mask option, which we use as “selected”, is
shown
Exercise: How to take advantage of the Render Mask
1 Start 3ds Max and open the file render-mask_2011.max, located in the folder E-book-
V-Ray-3.0;
2 Click on render and wait several minutes until it has finished, Figure VR3-12;
3 Now change the surface properties of just one object in the scene, for example,
transform the chair from opaque to glossy (see Materials from page 62 of Photography
& Rendering with V-Ray);
4 Go to the “Image Sampler (Antialiasing)” panel and choose Selected from the Render
Mask drop-down menu, Figure VR3-13, then select the object whose surface properties you have just changed;
As far as the new and very useful Render Mask option is concerned, let’s carry out a little exercise which will clearly show its functioning and related advantages without mincing words
Trang 12E-book: V-RAY 3.0 NEW FEATURES
Notes: If you click on render and nothing happens, you have probably left the Render
Mask set to “Selected” and haven’t selected any objects
Figure VR3-14
Image showing the render carried out only
on selected objects
CONTENTS
11
5 By clicking on render you’ll see that the calculation is only carried out on the selected
object, making the correction in just a few seconds, Figure VR3-14 This prevents you
from having to recalculate other parts of the scene, which would certainly have made
the rendering time longer
In a way the Render Mask is the evolution of Region Render It allows you to render very
specific areas based on a mask, a layer or - as we have just seen - on one or more selected
objects
Trang 13Notes: This change had already been made in the latest versions of V-Ray 2.0, but seeing
as they appear separate in the book, we prefer to emphasize it
Figure VR3-15
V-Ray Frame Buffer graphics window showing the buttons for the functions Force Color Clamping (A) and View Clamped Colors
(B)
Figure VR3-16
Part of the V-Ray Frame Buffer graphics window showing the buttons to access Pixel information (C) and gamma compensation (D), and a box containing the pixel information and the Corrected colors option
V-Ray Frame Buffer
The new V-Ray Frame Buffer, Figure VR3-15, contains new functions particularly related to color correction and to other slight variations Let’s start with the latter
1 The buttons A and B, Figure VR3-15, respectively Force Color Clamping and View
Clamped Colors, have been grouped under the same button Simply hold it down for a
few seconds to access both options, which are described in the book;
2 The button in Figure VR3-16 shows a preview of the effect of the gamma compensation,
which is no longer called sRGB It now shows the symbol of a gamma curve but the
effect and meaning are still the same
A B
Trang 14E-book: V-RAY 3.0 NEW FEATURES
Notes: When the gamma curve button of the V-Ray Frame Buffer (shown with a “D” in
Figure VR3-16) is active, to measure the real value of the pixel, you need to enable the
Corrected Colors option This can be accessed by clicking the third button “i”, Figure
VR3-16 (C).
Figure VR3-17
The color correction options highlighted
Select the checkboxes to enable them and see the effects they have on the image.
CONTENTS
13
As far as new features are concerned, it’s a good idea to mention the Color Correction panel,
which is still accessed as in the previous versions, by clicking the first button of the VFB Show
Corrections Control Now, finally, we are also able to change the Hue/Saturation and Color
Balance, Figure VR3-17
For more new functions or improvements, visit the Features section, under V-Ray for 3ds
Max, on the official website http://www.v-ray.com.