Viz R3i mesh/patch problem

[STRAT]

Hi there.

 

i had this problem for years now. i think maybe it be a bug. using viz 3i btw.

 

sometimes i create a simple box in viz, say about 10 meters by about 30 meters. create an omni and give it a raytraced shadow. every thing simple and standard here.

 

when i render i seem to be getting a dirty 'shadow' edge along the edges of my cube. this is worse obviously when i zoom in real close to a corner for example. go try it.

 

i've played with the shadow settings but it dont effect anything. then i converted the cube to an editable patch (not mesh) and turned the patch settings right down. i still getting this problem.

Then at the bottom of the edit patch modifier i notice an option called 'surface' which gives me the option to change render steps. if i jack this up high the shitty 'shadow' or 'edge' im getting is elliminated, but the render times shoot up.

 

anybody come across this problem before? why should a raytraced shadow light give edge shadow problems to a mesh and not a patch? wat to do....

 

i'll try post up a piccy real soon.....

[STRAT]

k. here we go (i hope)

 

image 1 - simple scene set up. 1 box (no materials) 1 raytraced shad omni.....

 

image 2 - zoomed in on the corner face and did a full anti alias render. notice darkened edges?

 

image 3 - zoomed right in on the corner point and hit render. look at that! wtf? AA settings, material settings, light set ups dont make a difference.

 

image 4 - i converted the box to an editable patch and jacked up the render steps to 30 instead of standard 5. render time slows but the 'edge' gets better. not wonderfull by any means, but gets noticably better.

[quizzy]

in the shadow settings of that omni, set the bias wich is located in the "ray traced shadow params"-rollout to about 0,3~0,5 and try again... this should work..

O, I never use omni's with ray traced shadow... its also VERY heavy to render...

 

This problem is in also in 3dsmax so.. here are some piccy's:

 

bias=0,2

 

bias=0,5

 

bias=1

 

bias=13 look what it does with the shadow in the bottom near corner...

[STRAT]

quizzy - ta for looking. the bias needs to be 0,0 to keep it accurate. also i get same render speeds using a raytraced shadow either with a omni or a spot.

 

go see this thread http://www.maxforums.org/forum/forum.asp?t=54799&r=17 i been thrashing this problem out all morning in maxforums.org