mentay ray exterior rendering (unchallenge)

[Sirk zalavarria]

hey guys!!!

ayv been searching and searching the web for a decent exterior rendering using mental ray. unfortunately, interior renderings are only available. so, as a last resort, am asking tips and suggestions on how to improve this rendering. also, this is in meters.

here are the specs for the rendering
1.) materials:
a.) wall color - architectural material - paint flat - white
b.) red and yellow accents - architectural material - paint glossy
c.) grass - normal grass bump map
d.) glass - mental ray material - dielectric material
d.1 light persistence - light blue
d.2 index of refraction - 2.0
d.3 outside light persistence - dark blue
d.4 persistence distance - .025 m.
d.5 phong coefficient - 60

2.) lights
a.) spotlight with raytraced shadows, multiplier of 1.0, falloff of 150 with overshoot on.
b.) skylight with multiplier of 0.5

3.) mental ray settings
a.) gi photons - 50000 with radius of .6 m
b.) photons(c&gi) with 100 samples
c.) final gather with 100 samples
d.) global light properties
d.1 energy decay 200000
d.2 decay 2.0
d.3 caustic photons 10000
d.4 gi photons 50000

so here a bunch of my problems...
1.) the glass material is so fake, how to improve it, what mental ray shader to use?
2.) the grass is very fake as well. how to make realistic without using any expensive textures.

also, criticism is highly recommended. i hope this thread will benefit millions of mental ray users especially those who are in the field of architectural visualization. i hope this will answer the mental ray exterior rendering tutorial request.

P.S. special mention to Mr. William Alexander(WDA), Alex Guzman (GI DUDE), Architect John Garcia (Voltaire Ira), Philip De keersmaecker (joske). thank you very much for the replies in my last thread regarding exterior rendering tutorial. thanks!!! (daghan salamat!) <----- how we say thank you in our place!!!!

[William Alexander]

Hey Sirkus,

Looks like a good start, but the resolution and view make it hard to really critique. Could you post just the model with the settings as you have them. Maybe myself and others could have a go at it and post settings, rendering times and images. Then show the scene refined and point out some of the detials that work and where there are problems and talk about their workflow of rendering with MR exteriors....

WDA

[Sirk zalavarria]

sir william,

thanks for the reply... attached the max file. hoping for your reply. thanx again

[Philip De keersmaecker]

first of you might wanna go for less hard shadows from the sun... this could be because your using a skylight?

IMexp it is better to use 4-6 Mr aera omnis instead of a skylight.
i don't seem to get any good results using the skylight sofar.
this 'omnis workaround' does give a good controlable 'skylight'.

I did test other GI solutions : Vray free and FR stage 1 demo, they have no 'skylight' object like in max/Mray but just a general setting for a 'skylight' effect, but they seem to work better... at first glance?...

for Mray interiors I allready gave up on using the max skylight, now i'm doing some outdoor scene's testing the workaround solution decribed above with acceptable results sofar...

i'll have a look at your scene if i find some time, my pc is currently rendering...

2nd about the grass : go out and try to find a nice garden from the neighbours to have your dog take dum... lol just kiddin'
and try to take a nice digital picture to use as grass texture, works great and you'll have real looking grass that doesn't have repetative tiles like the grass that's included in max and viz.

later duderinos

[Juan Carlos Rosalejos]

Here's how I did your scene.

1 Standard Direct light; value: 1
1 standard skylight; value .8
raytraced shadow
architectural materials
logarithmic exposure

Render:
FG only set to 1000 samples
4,16 sampling rate using Lanczos AA filter
00:03:11 minutes to compute and render on a 2.8 P4 2GB ram HT enabled


a few adjustments to the parameters.

[Sirk zalavarria]

hey jucaro,

thanks for the reply. i've tried your settings. however, it's not as clean and refined as your renderings. so i would like to ask you the following questions:

1.) what's your logarithmic exposure control settings?
2.) how do you know what filter to use? (i.e mitchell, lanczos ....)
3.) did you enable overshoot in your directional light?
4.) did you use the materials in the model or modified it?

joske,

i'll be waiting for your post. i'll wait for the settings using omni lights.

thanx AgAin!!!

[John Voltaire Garcia]

kris,

here's my shot using mental ray. this one was rendered using the ff. settings:

mr area spot mult = 1 color = pale yellow
skylight with an hdri map

logarithmic exposure control
brightness 50%
contrast 75%
affect environment map checked

indirrect ilumination settings
photons samples = 1000
radius = 1.0m
samples = 1000
radius = 1.0m

final gather =
samples = 1000
max radius= 13.34m
min radius = 1.3m

global light settings
all default except gi photons set to 100,000

rendertime = 8:21 using my
p4 3.0 ghz 512 mb ram notebook

[John Voltaire Garcia]

by the way, the sky can be changed. my sky here is quite dull since its a hdri map.but render it as tga then replace a new sky in ps.adjust the saturation to match the render.this one would be a late afternoon render maybe right after or before a storm.

[Juan Carlos Rosalejos]

hey jucaro,

1.) what's your logarithmic exposure control settings?
2.) how do you know what filter to use? (i.e mitchell, lanczos ....)
3.) did you enable overshoot in your directional light?
4.) did you use the materials in the model or modified it?

loga settings:

60
65
1.0
65,000

checked:
color corrections
Desaturate low levels
Exterior Daylight

Filter to use:
Its just personal preference. I like lanczos because it produces sharp results at the cost of a little notch on the render time.

Overshoot enabled.

The materials were from your file except for the grass which is from my library

[Philip De keersmaecker]

jucaro did you use photons - photonGI?
or just only the Fgather?

using photons requiers a normal flipped sphere around the scene (otherwise photons shoot into infinity) but the sphere blocks out the skylight...

so thats why i use the 4-6 omnis instead of the skylight...