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Glow where shadows should be


cadjockey
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Hi all,

 

I am rendering an interior view using a daylight system. The results are quite good subject to further adjustments however, there is a glow in places that I would expect a shadow to be eg. under the sofa and coffe table.

 

What could be causing this?

 

cadjockey

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Justin,

 

I have followed the tutorial which ships with viz on how to render an interior scene using MR and FG. This tutorial uses a daylight system with mrsun & mrsky with the exterior daylight in the environment menu toggled off. The light is generates is very realistic.

 

I have attached a render which shows a glow in areas that I would expect to see shadow.

 

Any idea what is causing this?

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Please post your FG settings and the couch material settings

 

Off the top of my head it could be one of two things, iether FG samples being trapped or there are reflections on the materials.

 

Without the settings its difficult to say what to change.

 

JHV

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Justin,

 

Attached are the renderer, Indirect Illumination and Materil settings (leather) that I have used.

 

This scene was rendering ok (but with the glow) until I decided to change some materials to A&Dmi materials. I used the Matte template to create the material and applied a texture map. Everything started to go nuts after that.

 

See my other thread regarding materials rendering incorrectly.

 

http://www.cgarchitect.com/vb/24863-material-assignment-instance.html

 

AHHHHHH!

 

cadjockey

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What happens if you put a material override on everything?

 

- Create a grey material with the Matte A&D preset.

- Assign that to the material override in the Processing slot of the render dialogue.

- Disable the save FG to disk

- try these FG settings

 

desity 0,8

no of fg samples 150

interpolate 50

Bounces 3

Max depth 20

 

Nothing else seems out of place. Can you post the sun/sky settings as well as the exposure control.

 

JHV

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OK Justin,

 

I adjusted the settings and applied a grey A&D material to the Materials Overide control.

 

If I render with those settings and enable Read/Write to .fgm file I get the following (refer attached). You will also notice that the models which rendered black (dark brown) are still doing so.

 

If I render with Read/Write to .fgm disabled I get a completely black render.

 

cadjockey

 

PS: I am getting an error message when I render that tells me the sun in the daylight system is using a shadow generator that is unsupported and raytraced shadows will be used instead. I cannot see any control which allows me the option to selct otherwise. This option is only available if I use IIESun.

 

Any assistance you can offer is appreciated.

 

My deadline is looming.

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Just found the post about unrecognisable shadow generators. Its from the Max-rendering forum on the Area.

 

Here is the what was written.

 

"Okay, Maxscript to the rescue!,,,,

I open the MR Sun+Sky Assembly, select the Sun, and type in the

Listener:

 

$

$mr_Sun:MR Daylight int Sun @ [-433.299133,-97.046768,169.393768]

 

(LET'S CHECK OUT THE AVAILABLE PROPERTIES:)

showproperties $

(...bunch of stuff we don't care about...)

.shadowGenerator : value

 

(LET'S SEE WHAT IT'S SET TO:)

$.shadowGenerator

Adv__Ray_Traced:Adv__Ray_Traced

(AHA!!)

 

(LET'S TRY TO CHANGE IT:)

$.shadowGenerator=raytraceShadow()

raytraceShadow:raytraceShadow

(SUCCESS!)"

 

JHV

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Justin,

 

I tried the listener but it is a little beyond my expertise right now.

 

Can you please expand on the steps I need to take?

 

I can open up the listener after I have selected the daylight system. I get the following window (see attached).

 

Where to from here? I assume I simple cut and paste this code.

 

$

$mr_Sun:MR Daylight int Sun @ [-433.299133,-97.046768,169.393768]

 

What next?

 

Sorry for the ignorance.

 

Your time and patience is appreciated.

 

cadjockey

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A little tricky by here goes

 

1)Select the daylight system

2)in the menu tab GROUP/ASSEMBLY/OPEN

3)select the sun

4)open the listener and type in showproperties$

this will list all the suns properties

5)type in $.shadowGenerator

this will list what type of shadows are being generated, if it lists anything other than "raytraceShadow:raytraceShadow", then change it to "raytraceShadow:raytraceShadow" . (leave out the " ")

 

JHV

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Hi Justin,

 

Thanks for that.

 

I get to the point where I replace the text with :raytraceShadow:raytraceShadow, press enter and get this:

 

-- Syntax error: at keyword parameter, expected

-- In line: raytraceShadow:r

 

What have I broken?

Sorry mate! Nothing is every straight forward with me.

cadjockey

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Hi Justin,

 

I copied and pasted it. Same problem.

 

This is what I am doing

 

- type in

$.shadowGenerator and get :

Adv__Ray_Traced:Adv__Ray_Traced

- Delete

Adv__Ray_Traced:Adv__Ray_Traced

- Replace with

$.shadowGenerator=raytraceShadow()

raytraceShadow:raytraceShadow

-Press enter and I get this :

Syntax error: at keyword parameter, expected

In line: raytraceShadow:r

Do I need to press save or something like that?

Sorry. Never used the Listener before.

cadjockey

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try this

 

do a search on your c:drive for CurrentDefaults.ini

find the one for mentalray and open it in note pad

 

Within the ini scroll down intil you find Natural Light Assembly, you will see that the mrsun is set to Advanced raytrace. I have highlighted the lines that are important

 

; Natural Light Assembly

; Sun

; No Sun = 0 0

; Standard Sun = 0x1013 0

; IES Sun = 0x23fe7f4f 0x06cf2fe9

; mrSun = 0x71503bbb 0x25e21124

; Sky

; No Sky = 0 0

; Skylight = 0x7bf61478 0x522e4705

; IES Sky = 0x4b241b11 0x64e8527d

; mrSky = 0x26ee3350 0x799b5b56

; Sun Shadow Generator

; Shadow Map = 0x100 0

; Ray Traced Shadows = 0x200 0

; Area Shadows = 0x1721305e 0x689452a1

; Advanced Ray Trace Shadows = 0x20016d4e 0x58ab60f8

; Mental Ray Shadow Map = 0x50c0a72e 0x3e2be365

[50 4a1e6deb 31c77d57]

; mrSun

sun=0x71503bbb 0x25e21124

; Ray Traced Shadows

sunShadowGenerator=0x200 0

sunCastShadows=1

sunUseGlobalShadowSettings=0

sunOvershoot=1

sunColor=255 242.25 229.5

; Skylight

sky=0x26ee3350 0x799b5b56

 

; Sunlight System

; Sun Shadow Generator

; Shadow Map = 0x100 0

; Ray Traced Shadows = 0x200 0

; Area Shadows = 0x1721305e 0x689452a1

; Advanced Ray Trace Shadows = 0x20016d4e 0x58ab60f8

; Mental Ray Shadow Map = 0x50c0a72e 0x3e2be365

[60 5897670e 61b5008d]

; Ray Traced Shadows

sunShadowGenerator=0x200 0

sunCastShadows=1

sunUseGlobalShadowSettings=0

sunOvershoot=1

sunColor=225 225 225

 

Save the ini, and open max. do the $.shadowGenerator and see what the read out is. hopefully it will be the raytrace shadows

 

JHV

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cant say for sure, try deleting the max.ini file. it will be recreated with the factory defaults. Its a long shot but it might work.

 

I suspect that the mrsun has somehow been set to use the global default shadows. This is a legacy setting from way back when. For the life of me I cant remember how to change the global default shadow settings. It was a pain then just as it is now

 

I'll keep on delving on this side.

 

JHV

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