Hey everyone,
Im looking for some feedback on what might cause reflections and refrractions to “dance” from frame to frame. Take a look at this movie.
http://www.bentimagelab.com/pub/video/max/shot2-reflectionDance1.mov
The object seems to pop from frame. It looks like the normals are re-calculated wrong in some frames. I have turned up the reflection and refraction subdivisions but it’s still there.
Any suggestions appreciated.
Ruffstuff
woah weird.
What are your render settings?
What moving objects do you have in your scene?
Its not a problem with the subdvis of the materials, it might be something like the nrm or dist thres of the IR map
is interpolation on?
How weird, are the meshes animated in any way? You might try to collapse them to editable meshes (not editable polys) and see if it helps.
Best regards,
Vlado
Why not edit Polys Vlado? Just curious.
Do you have a noise map in the bump slot that may have been accidentally animated? It looks like animated phase in a noise map. Thats my shot in the dark.
Because editable polys are, at some point, converted to triangle meshes, but strictly speaking, there is no guarantee that they will always be converted in same way every single time. If the triangulation changes, it may cause differences in the surface normals. I don’t know if this is what happens here though, without looking at the scene.
Best regards,
Vlado
I am really curious about what could be causing this. I’ve never seen something like that since the boolean-type geometry chopping back in 1.09…
The closest to this effect i got was when u rendered an image in slices and it didnt match perfectly…Or it could happen rendering an animation with distributed rendering?
To answer some questions…
Im using irradiance map for Primary and Light cache for secondary. My irradiance map is set to -3 -2 with a clr thresh of .2 and that give me almost no flicker.
There are no bump maps in volved and nothing is animated on this object.
My first guess was that the the normals were getting converted wrong. The comment about using editable mesh instead seems to make a lot of sense.
I will give that a try and let you know. Thanks guys.
no displacement on this either?
Seems to be reacting to the water that is off screen some how. Really odd.
Subdivision surface
My first question is are you using motion blur ?
The second question is have you used the World Space Subdivision surface modifier on any of your objects ?
If so that could be your problem. I am working on some shiny shiny stuff again and thought I could subdivide my way out of a tricky bit of modelling. It renders fine ( well it isn’t a great model ) if I don’t use motion blur, but if I do use blur, it creates weird artifacts, that look similar to your problem. You might also check if you have used optimize on any of your objects, that sometimes cause problems.
There are some frames below, that are from my current project - of course it is all top secret and junk - I think you might just guess this one though 
It should look like this …
But the next frame of animation looks like this …
hmmmm i wonder what movie thats from???
Yeh big pitch tomorrow
Yeh big pitch tomorrow - I couldn’t be arsed cropping the frame, I’m still in work at 9pm worked until 10pm last night.
You can try to collapse this modifier then… should help.
Best regards,
Vlado
Awesome!
It looks like changing it to an editable mesh fixed the problem. Whew, that was driving me nuts.
Thanks
Ruff stuff
I’ve never used the world space subdivide modifier with motion blur. I wonder if it is changing the # of verts since it’s in world space. I could see that causing problems with motion blur.
I only used the subdivide modifier when I have normal problems. Like a chamfer box without a lot of subdivisions. I never realized that the lack of geometry would cause poping with Vray.
ruffstuff