View Full Version : how to specify final gather radius ?

01 January 2006, 06:08 PM
hi all
I 'm new to mental ray . . well i achieve what i want when i comes to still images. but when i ve a animated scene i 'm really frustrated to get a output without flickering with GI. I'm working on mental ray with out any help for allthese days but i couldn't figure out what the problem is. . I'm also a bit confused like how to find the scale of the scene.e. . . i would be glad if someone could help me.
thanks in advance

Ian Jones
01 January 2006, 10:22 AM
software? you should really check the in-built tutorials in your software... I'm sure there is information about your question.

02 February 2006, 06:08 AM
hey man, ok i got this info from mr user i dont know is it true ...anyways i will tell what i know ..ok.. the scene has a house or a room or anything what u got to do is use a mesuring tool or just creat a temporary poly plane dont scale it just increase it height and width....and it should be a square try to fit ur scene on the square and when it does not it size either width or height because they both are the same ...and for example it is 50 then u max radius is 50/10 that is 5 and min radius is MaxRadius/10 that is 5/10 that is .5 i hope i am right but if i am not please do correct me ...i dont mean to pass wrong information ...
Ankit Sharma

mr Bob
02 February 2006, 10:04 PM
Hi Ministry.

Flickering can be caused by a number of issues when using MR but the main one is when final gathering is used you can get flickering from the bump maps on your materials as final gathering actually looks at the bump values on your objects, you can get round this by using a raytype node to detract the bump calculation from the FG calculation.
Also you might find rebuilding your FG map at everyframe helps.

With the min radius and max radius , the min radius is the smallest distance between 2 objects in your scene and the max radius is the largest.
Hope this helps. Keep everyone informed with how your going ...


02 February 2006, 05:58 PM
Hello There this a litt;e script i wrote to set the min and max. read the notes at the beginig. Enjoy.

/*Usually, the Max Radius setting will be about 10% of the size of your

scene, and the Min Radius is 10% of the Max Radius. You can find out

the size of your scene by using the "Create > Measuring Tools > Distance Tool".*/

global proc fgMinMax( )


if ( (`window -exists fgMinMaxname`) == true ) deleteUI fgMinMaxname;

window -title "FG Min/Max radius " -wh 400 100 fgMinMaxname;

columnLayout -adjustableColumn true;

floatFieldGrp -label "Distance Across" numberStrings;

button -l "Set Min Max Radius " -c "minMax";

showWindow fgMinMaxname;



global proc minMax( )


//string $select[] = `ls -sl`;

float $number[] = ` floatFieldGrp -q -v numberStrings `;

float $ten = 10;

float $max = $number[0] /$ten;

float $min = $max / $ten;

setAttr "miDefaultOptions.finalGather" 1;

setAttr "miDefaultOptions.finalGatherMinRadius" $min;

setAttr "miDefaultOptions.finalGatherMaxRadius" $max;



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