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Found 13 results

  1. Relative Flatness

    Hi, i am trying to make a mask based on the relative flatness of my mesh or relative curvature? i am not sure how to put it. i have a rock with bumps everywhere obviously but you can clearly see areas where in general it is flat although there are small bumps, you can distinguish relatively flat surfaces by eye. i tried generating the curvature map and then blurring it but the results are not that good. They are soft after the blur and not precise. the other thing i tried is clustering by normal -6 clusters- for a box like projection if you will. but the problem with clustering is yuo have to decide the number of clusters. i would prefer a threshold of normal similarity. thats what i will try to do next
  2. Manipulating Camera RAYS in mantra

    as you can see in the image below, the massive gravitational energy of the black hole bend the fabric of universe, on of the way to create such a phenomena is to bend the rays that emit from camera to produce something link black hole effect. are there any vex function or vop node that can manipulate the camera rays in mantra? I was thinking about creating some curve and assign their tangent attribute to camera rays. is that possible? or I can create a fake geometry.
  3. Hi Im creating a cliff in Houdini. I have the blockout of the big shapes, but now I want to cast some smaller rocks in between cracks and edges (concave). I'm using the Measure Curvature node to get a black/white mask of the curvature. But I don't know how I can use this colour information to create a mask on where to spawn smaller rocks. I test things out by copying a simple sphere to points but this gives me the shape of the rocks filled with the sphere. I've only found this youtube video of the curvature node: But they just skim over the nodes. Im completely stuck. Anyone an idea? Thanks!
  4. i want to scatter points on a deforming mesh (a growing mesh) based on its curvature attribute. currently they are appearing and disappearing as the curvature values are changing (based on the deforming mesh) every frame. however i want them not to disappear once they are created and stick to their original position they were created (as closely as they can). PS: the deforming mesh is generated from a vdb sdf. i am using a triplanar UV on it. i would highly appreciate any tips and help.
  5. How to group prims by similar curvature

    Hi, I'm a relatively new user so forgive me if this is a trivial problem I'm trying to sort my mesh according to regions of similar curvature. My aim is to be able to iterate over each region and remesh it smoothly— Ideally, in a way that would preserve boundary points and leave the mesh water-tight. Below is a link to the work of a Houdini artist whose procedure I'm trying to reproduce on my own meshes. Any help or a nudge in the right direction would be much appreciated. I've attached a very simple hip file illustrating what I'm trying to accomplish. Thanks so much! Measured Partitioning_test.hiplc
  6. problems measuring curvature

    Hello Friends, I'm back again with what is surely some novice misunderstanding of the tools. Basically, I'm trying to get edge damage by measuring curvature and binding that within a point vop. However, I realized that my curvature is not being correctly measured. Instead of having the high points in the apex of the rounded edge, my gradient has the greenest result in the highest part of the rounded edge. Furthermore, inside the actual point vop, this 'mask' is only revealed if I use the concavity attribute... I don't mind calling it the wrong thing - but I'd like to have this result have the highlight on the apex of the rounded edges. Anyone know what I'm doing wrong? Thanks, p curvature.hip
  7. My wire simulation issue...

    Hello; I have some lines in my simple " Wire " DOP, and I want them to act as soft elastic tubes. I don't know why they bend up, instead of bending down! So, how can I fix this? Thanks for helping. WireLines_01.hip
  8. Hi, As the title says, how, mathematically speaking, can I set points on a curve based on its curvature? What do I need to learn to do this? Trigonometry and derivatives? Thank you
  9. Hey all, I'm using houdini 15.5 and I'm trying to expose edges (in a manner similar to vray curvature/ inverted ao- https://docs.chaosgroup.com/download/attachments/12085592/VRayCurvatureHero.png?version=4&modificationDate=1487005362000&api=v2), the manual says "If the negated normal is connected, will find exposed edges. @parameters" so I took global variables, took the P plugged it into the P, took the N and added negate node (also I tried multiply constant with -1 instead) and plugged it into nN, the bias direction is 0, 0, 0, and still all I'm seeing is occlusion dirt, same as with default settings. I know that there's a 'curvature' VOP, but it yields some weird results for me, so I would like to try the dirt instead and see if it's different, so please help:)
  10. Hey everyone! Here's a demo of some point cloud tools I created to calculate concave and convex curvature as well as gradient and curl direction, also sharpening. Forgot to mention in the demo that the curvature calculation is a great way to do differential growth by advection along normal * curve * noise * parm. Also, the curl calculation can be used to make grass patches and groom fur by orienting curves along the direction to add swirly variance. There's a lot of ways these tools can be handy, interested to see what you all come up with! Let me know if you have any questions, enjoy! curveGradientCurlSharpen_v002.hipnc
  11. Hi Guys, After painting a lot of edge scuffs/rust/drips in I was fed up with the tedious labor of doing everything by hand. Especially when the stuff you do is almost always the same 'trick'. Is it possible to recreate something like this in vops? http://www.artonbit.com/cinema4d-corner/cine-tools/item/45-surface-curvature-shader This is btw the closest I could get in my search: http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=13855&postdays=0&postorder=asc&start=25 Thanks in advanced guys!
  12. please guys i have two vectors for point and i wanna know how to compute the curvature from it in vopsop what math method i should use guys
  13. Hi, I was trying to use the measure sop and the curvature mode to filter the flat part of my object and emit only from curved area but I didn't find very successul, does anyone know any other way to filter those areas ? Thanks ! Chistof