rob Posted March 20, 2008 Share Posted March 20, 2008 Hi people , I'm doing a small animated feather as a challenge and I have a need to add wispy strands , wanting to stay clear of hair. I have opted for using lines , which I figured would be the way to go as I could add a sin wave and noise to them which in turn could be animated over time. The biggest issues i am having are the AA of the line width attribute and the fact the line renders as a line .... I know . What can I do to fix this and get those wispy strands I'm after ? . It would also be handy to be able to have the colour at the root graduate up to the tip ... Quote Link to comment Share on other sites More sharing options...
rdg Posted March 20, 2008 Share Posted March 20, 2008 Hi people , I'm doing a small animated feather as a challenge and I have a need to add wispy strands , wanting to stay clear of hair. I have opted for using lines , which I figured would be the way to go as I could add a sin wave and noise to them which in turn could be animated over time.The biggest issues i am having are the AA of the line width attribute and the fact the line renders as a line .... I know . What can I do to fix this and get those wispy strands I'm after ? . It would also be handy to be able to have the colour at the root graduate up to the tip ... the point color will be blended over the length of the line. If you assign different colors/saturations to root and tip points you will be fine. and maybe use a semi-translucent shader. maybe you need to up the image sampling from 3x3 to a higher value to get rid of the aliasing. Georg Quote Link to comment Share on other sites More sharing options...
rob Posted March 20, 2008 Author Share Posted March 20, 2008 The first thing I did was pump up the image sampling , that image had 9 x 9 . Quote Link to comment Share on other sites More sharing options...
sibarrick Posted March 20, 2008 Share Posted March 20, 2008 Weird, it looks like no sampling. Are you specifying a valid camera? Quote Link to comment Share on other sites More sharing options...
rob Posted March 20, 2008 Author Share Posted March 20, 2008 (edited) Well After some tweeking around I have got some improvement but its by no means great at all , Ive upped the samples to 13 x 13 and confirmed the render is through the camera. I am driving the width attribute through the expression 0.006* (1-$BBZ) . Im at a bit of a loss. Increasing the shading value on the geometry node does'nt effect it much at all R Edited March 20, 2008 by rob Quote Link to comment Share on other sites More sharing options...
symek Posted March 20, 2008 Share Posted March 20, 2008 Increasing Shading Quality would be blessed here. 2 or 3 even. Quote Link to comment Share on other sites More sharing options...
rob Posted March 21, 2008 Author Share Posted March 21, 2008 That has no effect at all Rob Quote Link to comment Share on other sites More sharing options...
Jason Posted March 21, 2008 Share Posted March 21, 2008 Not sure why your scene is not responding, but in this scene if I increase the Pixel Samples on the Mantra ROP, the lines get incredibly smooth. finewires.hip.gz Quote Link to comment Share on other sites More sharing options...
AdamJ Posted March 21, 2008 Share Posted March 21, 2008 Another thing to try is set your 'Properties->Pixel Filter to Gaussian 3 3'. It will soften the render but for furry stuff it might help. Quote Link to comment Share on other sites More sharing options...
sibarrick Posted March 21, 2008 Share Posted March 21, 2008 Can you post a hip file? looks like something is fundamentally wrong here. Quote Link to comment Share on other sites More sharing options...
rob Posted March 25, 2008 Author Share Posted March 25, 2008 Sure I will post up a file very soon. Im really trying to push Houdini ( trial ) on a short project and I have had to move on trying to find out the workflow for other parts of the project. R Quote Link to comment Share on other sites More sharing options...
sibarrick Posted March 25, 2008 Share Posted March 25, 2008 Ok, rest assured it will work, there must just be something wrong in the current setup. Quote Link to comment Share on other sites More sharing options...
old school Posted March 25, 2008 Share Posted March 25, 2008 Right now you are rendering flat ribbons. Many hair shaders render the flat wire as a tube by either displacing the wires in to a half cylinder or in a surface shader by bending the normals. This will allow the hairs to catch the light in a more realistic way. The default Fur material has a new VOP called hairnormal which warps surface normals to approximate a half round tube. That may help in the shading. As for the wire geometry, as Jason said: Pixel Samples Quote Link to comment Share on other sites More sharing options...
rob Posted March 25, 2008 Author Share Posted March 25, 2008 (edited) I figure as much , 99% of the time I guess its error 40 ( me sitting 40 inches from the screen ) ! . Jeff thanks for the pointer. Is there anything special as to how I should set this default fur material up ? or is it just a case of plug in and go ? . thanks rob Edited March 25, 2008 by rob Quote Link to comment Share on other sites More sharing options...
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