6 replies to this topic

[jim c]

So I tried my hand at creating a shader for a wire/curve, that takes a curve and allows you to animate how the curve "unrolls". It uses a simple particle system to create a trail of particles with an energy attribute. This is then used in the shader along with length and width ramps to create a glowy effect along the curve. So far, so good...except for these annoying points that seem to popup. I've done something stupid here, but I'm not seeing it! Any help would be most appreciated.

The goal is to turn this into a DA that I can then use on a more complex set of curves for my Tron project.


To view it, open the hip, and scrub to back to frame 0, then somewhere between 0 and 36 (that's where I've currently got keys).

Attached Thumbnails

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Attached Files

•  wire-test2.hipnc   188.38K   146 downloads

[jim c]

Well I feel a little stupid! It would appear that I still had the particle system in the SOP, which I really didn't need. Applying a Delete SOP for prim 0 just before the final Material node, seems to have deleted the particle system but leaving the attribute values intact. Is this the right thing to do? It certainly gets rid of the nasty little point artifacts.

[blackchicken]

Yes, your right, it is particle system which you must delete if you want only line with parameters. Good luck.

[jim c]

Thanks. I think I got it all sorted out, took a little more experimentation to get the sharp angles in the curve to be handled better, but it looks kind of cool. If anyone's interested I can post the hip file.

[zephyr707]

jim c, on 17 November 2011 - 11:11 AM, said:

Thanks. I think I got it all sorted out, took a little more experimentation to get the sharp angles in the curve to be handled better, but it looks kind of cool. If anyone's interested I can post the hip file.

hi jim,

hope this is not too late, but i'd be interested in taking a look at your final hip file.  I'm just downloading the first one and am taking a look at it.

thanks!
z

[gotfroi]

The wire bit is not rendering for me in Houdini 12, but those pesky particles do!

[gotfroi]

Oh, had to set Mantra to "Raytrace" to get this to render as advertised, and yeah, inserting the delete SOP with pattern set to "0" got rid of the particles.