flickering trees in Mental ray animations pls help

[KB-DEsign]

Hello i've found your plugin and was verry happy with it until i did an animation..it's fly through...it's a building suround by a forest (made by forest lite) i uses 2 d trees that came with forest lite but the thing is that they flicker in some areas....why is that? and how do i get round it? cause this REALLY starting to get on my nerves.....i've tried a lot of things but NOTHING seemd to work....i use 3ds max design 2011 with Mental ray.....PLS HELP ME

[iToo]

Flickering can be caused by geometry, GI, texturing, AA sampling or other issues.

Please, can you post some images and your render settings ? Or better, include a stripped scene with instructions to reproduce the problem. You can also send the files to our support email.

[KB-DEsign]

thank you for this fast reply.... i wrote an email to u ....i know it's a lot to ask but will you ckeck it out  before moday? deadline is verry near and i hope to do some rendering in the weakend.... well eather way thanx

[KB-DEsign]

well  my email was returned to me ......is your email carlosqg@itoosoft.com ? well i uploaded the file to rapidshare here's the link http://rapidshare.com/files/408618950/flickering_trees.zip

[KB-DEsign]

the instructions are.....i rendered the scene in frames in tga format....composed in after effects. i can render out from frame 20-60 and see the animation....cause camer movement start from frame 20. i precaluted final gather at the settings that you will see in the final gather tab. i don't what else.....ahm...i gues that's it all settings are the way they are when i get this problem....so you should see it when render and compose everything

[iToo]

Ok, this is a typical problem of the billboards when used on animations: If you play the animation from a top view, you can see how the billboards are rotating to face the camera, but sometimes the planes intersect between them because the high density of objects. This creates a flickering effect when rendering.

There are different solutions to this problem:

a) Enable Collisions. To get a similar density of trees from the original scene, select a "Dense" distribution map and adjust the "Density->Units" parameters.
b) Use a Two/Three/Four planes geometry for the trees and disable the "Camera->Trees Facing the camera" parameter. Using this configuration, you will need to adjust some illumination parameters. Suggested values: Material->Self-Illum factor = 100%, and set the RGB output value of the textures to 0.5 to darken them.
c) Use 3D trees. You will get the best result for animations, although render times will be higher. You can find some free 3D HQPlant trees in our website.

I also noticed some flickering effects in this scene caused by self-shadowing. To avoid it, disable the "Shadows->Raytrace->Every tree over itself" parameter. I also suggest to set "Camera->Limit to Visibility" parameter to off, or increase the "Expand" value to fix the popping effect of some trees.

[KB-DEsign]

thank you for your VERY quick responce, i will try betwen a) or b) because 3D trees are way too RAM consuming fellas, unless u can make forest lite to use then as mr proxies. and i am short on RAM. plus i don't know if i can afford myself to have longer renders because i'm short on time. thanx again. i will post how it went for me

[iToo]

Ok, but you can use mr proxies with Forest Lite in the same way than Forest Pro. Moreover, we suggest to use the high-poly objects directly, because Forest converts them internally to proxies, without any performance loss and using the same RAM.

[KB-DEsign]

i have only 2 GB of RAM and  i have 1.4 million polys in the scene and even now my animation crashes after rendering for about 30-40 frames. so i have to render the whole thing in peaces...i'm afraid that if i put 3d high quality trys that ir will bring my machine to it's knees...i will try c) if i will get myself a bit more time from the client....thanks again man you're a life saver