Hi…

Im a new bee and was verymuch interested the way houdini is working. the way I would expect anything to happen (procedural) is what houdini is doing. I appreciate sidefx for contributing such a marvelous techonology for everybdy as an apprentice edition. well after some time, I have designed a sequence and want to do it with L-systems(really great!!!) and render. but not able to do so as I have a less knowledge on this system plus the accompanied manuals dont help much on this matter.

My problem is, I want to create a nervous network using L-systems (yeah like fighting clubs opening scene :shock: !!) and add some bump maps, vex ops etc., etc., and render it. but in da first place Im unable to texture the tubes properly(my problem? :? ) and can't put on some abnormal displacements for the tubes. I dn't want massive tubes. but I need a very thin veins that should be rendered with multiple vexops on it.

If anybdy has some suggetions, please do so quickely. I have already pulled out half of my hairs and for no use!!! :cry:

Thank you all in advance.

Have you turned on “Apply Tube Texture Coordinates” on the tube tab. That should give you sensible uvs. Alternatively you could just use a displacement shader that works in world space rather than uv, like VEX Krinkle for example

Hi.. Thanks for the reply. but I had already tryed that and not getting the look what I need :cry: . let be explain this clearly…

I have a L system with numerous branches, sub-branches etc., with the leaf inputs of some geo. what I need is, I want to specify a texture, displacement, glows etc., for the L-systems based on it's own local co-ordinates. with which, when the camera animates through the L-system flythrough, some parts of the L-system will glow depending on the camera position. but, what I see is, when ever I put a texture or some colord tubes, they act like some dumb things :roll: (I really don't understand what's happening :? ).

I tryed to apply some geo(metaball) to the L-sys but they were not satisfying as the output of the tubes is. I need to render tubes(or some geo for the l-sys) with specific textures.

I need some help. please point out to some thing or some where I could get a solution.

bye tha way thanks for seeing and replying.

Hi ravindra.
If you only need to activate some effect depending where your camera is maybe you can use a metaball parented to the camera and use attribTransfer to activate for example and attributte named “glow” that you can use in you shader to activate the effect. the metaball should transfer the attribute to the l-system when the camera is close to it.
See the attrib transfer tutorial:
hdox/houdini/content/base/tutorials/fm_07_guide_character_1024989.xml
If you need the relative position between the camera and the l-system maybe CHOPs are your tools, specially Object CHOP, you can use it to control your glow shader.
Another option, render a mask using the previous tools, and use it in halo to create the glow in post.

hi.. thank you for the help. well, Im checking the link now. well, is there any way to create geometry that fits the L-systems? like skin?(didn't work!) metaball? or any thing else?

bye.. Im checking the possibilities right now. agn.. thank u very much

Have you tried the PolyWire SOP?

You certainly can, i'm fairly certain its not the most efficient way, but if you put a leaf node every other step or so, and make that leaf a metaball, you get a nice smooth, vaguely blobby skin of the lsystem.

and then i shaded it with a variant of the IDGloop shader, which gave a nice bumpy sort of look (i was doing a piece of coral)

for the glow thing, i'm not entirely sure how to do it in houdini, but in maya i used a node which returns the distance between a transform node and a point being shaded. mebe there is something similar in houdini? the handy thing with that was that it didn't need uv coordinates.