Same topic as posted with “madnessglory” as I temporary used my friend's log in to create the post. I did some test on fur function at Houdini 10, mantra. The outcome of image sequence seems flickering a lot, and it happen same as the same after applying Dynamic. Confused

At first I kind of suspect the flickering may causes by shadow map, therefore I changed from Ray-trace shadow to Depth Map shadow, by doing so the rendering time had been shorten up and faster but yet it still flicker when the camera moves around or either the character is moving. I'm not sure what is the problem that causing the flickering, it seems nice and pretty when it's a still image, but it's totally out of question when the is a animation. The following is the setting I'm having now.

Shader
-fur shader sample dicing : 2

light
-Light type: spot light
-Shadow type: Depth Map Shadow
-Shadow bias: 0.08
-Shadow Intensity: 1
-Shadow Quality: 10
-Shadow Softens: 5
-Auto-generate Shadow Map: checked (on)
-Shadow Map sequence: created
-Resolution: 2048 x 2048
-Pixel sample: 3 x 3

Render setting
Render Engine: Micropolygon Rendering
sampling Sample Pixel: 8 x 8

Is there any way to solve the problem, should I use PBR rendering???? It would be an expensive way for the machine that I'm on.

Here is a clip of the fur test after i throw away the dynamic and just a rotation on the character itself. The flickering is pretty obvious.

As Eetu did mention for the transparency…is it the opacity on the fur material that created by default when we apply fur on the object? as the image below?

Thanks for TheUsualAlex and pclaes for recommendation.

I did another test again after that, with increase object's Shading Quality, Dicing from 1 to 2, and did a rest position in the Object channel by re-using a single frame of the sequence object file. to lock the object movement for rendering a still image of 30 frame sequence. It seems flickering have gone, so it's definitely not a bug or installing problem. It might be something wrong on the movement, just that i wonder how does the object file with rest position will work with animation, and rest post does lock down the animation?

hmm… think i should try on a animated ball for a faster test instead of a whole furry character to reduce the rendering time.

It must be the rest position that was missing then.

For animation the fur requires that the topology of the mesh is not changing (throughout the animation you have the same number of points.)

You could use the following workflow:

1) Load in your animated geometry with a File sop (or if it is coming from within houdini you can object merge).

2) create a rest sop

3) plug the animated geometry into the first input of the rest sop

4) create a timeshift sop, connect the output of the animated geometry into the timeshift.

5) on the Timeshift sop, delete the expression and set the Frame to 1

6) connect the output of the timeshift to the second input of the rest sop.


Next time try to keep your problem in one single thread as it is easier to track previous suggestions.

Pclaes, thanks for the advice and solution. It works.
The flickers have gone after applying the rest sop, and i did increased the shadow map, geometry shading quality, and mantra pixel sample. But somehow it's seem something wrong, i wander is it that the way it should be, I just not pretty sure about it. The rest position sop tend to lock down the dynamic movement of the fur, the fur seems not floating although it does move along with the object surface. Is it that the way it is?

Oops, solve the problem. Finally get to rest post with the same time of applying dynamic on fur, so that it floats. Cool. Just a fast testing without any adjust to the fur yet, as the result show there isn't any flickering and the shadow map seem alright.

light setting:
-Shadow map resolution : 1500x1500
-Pixel sample: 3x3

Mantra Render:
-Sampling sample: 8x8

Didn't know anything about Rigid Bodies, so i did another test by applying the Rigid Bodies > Static Object from SOP geometry on the fur so that it will lay on top of the floor but don't know why the first frame shows that the fur still intersect over the floor surface. As show in the clip http://www.sidefx.com/download.php?id=4880 [sidefx.com].

Although the things seem runs smooth for a little fur ball, but when i did a test on a fully fur character, the casting shadow seem to be not smooth enough, which i had been keep on increasing the shadow map quality to 2048x2048 and pixel 3x3, render output up to 10x10 sampling sample. Really have no idea how much value should i put. The rendering time is getting more and more expensive.

Am I increasing the wrong value? Or is there any solution to solve the shadow problem? I'm using a spot light to create the detail shadow map as i found some forum said that shadow map is better then ray-tracing shadow.

Rhino in Fur (just for fun):
Wondering why test fur on Rhino? ha. good question.
No doubt doing testing on a simple sphere will cut down the rendering time, but the outcome will definitely different with a completely build character because of the varied surface amount. So i add fur to an animated character of my colleague's work on walk cycle. Well, I always found that is much more interesting to do something out of box. Instead of painting a real rhino, which don't really have much fur, why not just paint it fully with fur just for fun to kill the bored of testing time and testing the render heaviness at the same time. Pretty cool huh? There is no harm to try, as a newbies nob on Houdini, my purpose is to test and practice tool usage for future project needs. And it did end up pretty cool.

yeah! I found the trick. Don't actually need to keep increase shadow map resolution and mantra render sample sampling. Why I starting to feel like i have been asking question and replying myself? haha, funny. Well, I'll try to arrange the tests that I did in a better order order and update here later next week. Hopefully it will provide some info for those have same question, might or might not be useful, just better then nothing.

Kind of found a simple trick to reduce shadow flickering.Well, the trick is to play with shadow bias and shadow blur, so that you won't be needing keep on incraesing shadw map resolution and sample pixel.

Besides that, light type is one of the effect that have been causing problem. So, i did a simple comaprison on different shadow blur value with differ light type and put togather as image to sees the differents. I knew it seems stupid, and it doesn't relate to the final object placement, but well it is individual just some notes for myown refer. I was testing same value setting and position for spot light and ditance light, comparing the outcome on shadow map. Although i really kind of like the spotlight lighting mood, but distance light's detail sahdow map is much more stable. It doens't mean spotlight is not working at all, just a higher value of shadow map resolution and sample pixel is needed if I insist with spotlight as major shadow map creation, which will require a much more expensive rendering time. And there is no specific amount for the value, it yet depend on your camera shot distance to play with shadow blur, a closer shot may require lesser blur and bias.

The more closeup the object are, the more fur is needed. Its all depend on how powerful your machine are. For my case, at the end, I separated into 2 layers in-order to push out the final fur density value that I want to have.

nuvelle
The more closeup the object are, the more fur is needed.

Do have a fur texture map on your model? That often helps. It's similar to how bump maps help to create more detail than there actually is (or often needed).

ohhh….. how come I never though of that. A layer of painted fur texture map and 3d fur on top. Greats, thanks, I try it right away. hoho.

Mind you, I've never tried it myself so your mileage will vary.

well, no harm to try, it might be good idea too.
So, I did some test with fur paint on texture map for body base texture. Theoretically, I think it works, the texture will somehow help to create a cheat on visually looks more fur. But it also have disadvantage, which it might have difficulty for realistic fur especially when the compositor artist wish to do some brightness or color adjustment. I believed they will kill me for doing so, haha. The weak point will show up right immediately when i toned up the brightness or color level. Therefore i combine painted fur texture with previous explore render way, it seem much more better then ever. Perhaps even double up the fur layers would be more density like. Cool, thanks for the comment. Discussion always the best way to get improve.

Clip: furry Rhino [vimeo.com]

Both looks cute to me, I wander should I maintain no fur or with fur..…..

More developmet: blog [nvspacehome.blogspot.com]