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VRay for 3ds Max Manual
Migration to V-Ray 1.5
While there are many new features in V-Ray 1.5, we have tried to keep the
compatibility with older V-Ray versions where this is possible.
Nevertheless, a few changes to the basic operation of the V-Ray rendering
engine were made. The most important of these are outlined below. Note that
there may be other changes not mentioned here.
V-Ray no longer uses randomized quasi-Monte Carlo (rQMC) sampling;
instead, a modified version of Schlick sampling is used for all blurry
values. For more information, see the
DMC
sampler section.
In previous V-Ray versions, increasing the Max
subdivs parameter could lead to increased noise in the renderings
when using direct GI evaluation, blurry reflections, area lights etc. This
was extremely obvious when using the
universal settings scenario. To compensate for this effect, a lower
Noise threshold for the DMC sampler was
required.
This is now corrected and increasing the Max
subdivs for the Adaptive DMC image sampler
keeps the same noise level without modifications to the
Noise threshold. This should be kept in mind
when working with older scenes where the Noise
threshold was reduced - they might render slower, although the noise
level will be much less. To reduce the render times again, you should
increase the Noise threshold or override it
by unchecking the Use rQMC sampler thresh.
option in the Adaptive rQMC image sampler
rollout.
There is a new option in the Color mapping
rollout - Subpixel mapping. The default value
for this option is off, since this produces more
accurate renderings. However, the behaviour of older V-Ray versions was as
though this option is always on. When combined
with Clamp output set to
on, this could cut off some of the noise in the image (e.g. isolated
bright dots caused by reflective or refractive GI caustics). This resulted
in incorrect (or biased) renderings, especially when using the
universal settings scenario, but perhaps visually more pleasing because
of the reduced noise.
In V-Ray 1.5, the default value for both the
Subpixel mapping and Clamp output
options is off. While this produces more correct
renderings, you may get isolated bright dots caused by reflective or
refractive caustics that did not appear with previous versions. To avoid
these, you should turn both options on.
Because the Clamp output option is now
off by default, very bright objects (e.g. area
lights or their reflections) may appear jagged despite good antialiasing
settings. To obtain smooth antialiasing for such objects like in older V-Ray
versions, turn the Clamp output
option
on.
Keep in mind that if you want to use the
universal settings scenario correctly, both these options must be at
their default values - turned off.
Since V-Ray now supports the 3ds Max render elements interface, the old
G-Buffer channels list has been removed from the renderer settings. Further
on, V-Ray automatically detects which G-Buffer channels are required by the
render effects and by the selected image output format (e.g. .rpf or .rla).
You have to use the specific V-Ray baking elements instead of the
standard 3ds Max ones (e.g. VRayCompleteMap
instead of CompleteMap etc).
The Normalize intensity option for the
V-Ray light has been replaced by the light Units
selector. Its action is most closely emulated by the
Luminous power units setting.
The Invisible option for the V-Ray light
now only affects the appearance of the light when it is directly seen by the
camera or through refractions. The visibility of the light with respect to
reflections is controlled by its Affect specular
and Affect reflections options.
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