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About MrBajt

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  1. Hello there, Is there any way to create Geo dynamically inside a dopnet? Specifically, i would like to have growing tendrils, and simulate those as they are created using popgrains. I created a popwrangle inside my dopnet, and created new points and primitives through vex. Unfortunately, that breaks the pop solver, as its not solving the newly created particles (However, if I put a force after the popsolver it works). I thought maybe that resetting the id to -1 (as used in a similiar way with the bullet solver) would do the trick, but unfortunately not. Is there any way that I can force the popsolver to recognize those newly created particles? Thanks in advance, Bajt createGeoinPop_v01.hiplc
  2. Hello there, I recently created a bunch of HDA's , and just now realized I created them on the Scene Level. So now I cant create the asset node in Geo Level. I need to stamp the Assets on a copy node, so I need to be able to create the asset in geo Level. Is there any possibility to convert my Scene Level Asset to a Geo Level Subnet? Best Regards, Bajt
  3. Access Bullet AutoFit Orientation

    Oh cool, I didn't think of looking in the point attributes, just in the DOP Subattributes. Good to know Thanks man
  4. Hello there, For my current project, I have a subset of randomly oriented geometry (mostly box or capsule like shapes) in one .obj I would like to orient all of them along their main axis. I remembered Bullet had a Autofit feature, that would fit specific geometry (Sphere, Box, Capsule, etc) to your geo. I tried looking up the source code for this, but I don't think the effort would be worth trying to understand the whole code (I'm a very beginner coder unfortunately), and secondly I think the bullet solver inside houdini does a pretty fast job as is. My approach is now to import all the objects to bullet, calculate the AutoFit there, and then get the orientation for each object. But how exactly can I access the Bullet Collision Orientation? In my subdata it shows no orientation (obviously, because my parent node is not rotated or transformed), and in the bullet data tab i cant seem to find any orientation. Is this even possible? Or can someone here share and explain the AutoFit code inside Bullet? (Just Kidding ;)) Best Regards Bajt *edit : I just remembered one more question, even though it's not directly related to this one: Is there a way to calculate the best fitting primitive for a shape? I read the paper https://www.cs.drexel.edu/~david/Classes/Papers/MeshlessDeformations_SIG05.pdf , but when i understand this correctly it only works if point numbers and number of point match in both point clouds. Maybe its possible with bullets autofit algorithm?
  5. Hello, For the sake of understanding perlin noise (and due to a little downtime during the holidays) I tried to implement a very simple approach to the perlin noise purely in VEX. I'm just a beginner in coding, so maybe this won't work at all, but for the life of me I can't seem to find a solution. Here's my code: float perlin(vector pos;vector freq) { float xi = floor((pos.x/freq.x)); float xmingridpos = xi*freq.x; float xmaxgridpos = xmingridpos+freq.x; //define a grid in x-direction float zi = floor((pos.z/freq.z)); float zmingridpos = zi*freq.z; float zmaxgridpos = zmingridpos+freq.z; //same in z-direction vector randvec1 = normalize(set(random(xmingridpos,40),0,random(zmingridpos,400)))*freq.x; //assign each corner of the cell a random vector vector randvec2 = normalize(set(random(xmingridpos,80),0,random(zmaxgridpos,800)))*freq.x; vector randvec3 = normalize(set(random(xmaxgridpos,120),0,random(zmingridpos,1200)))*freq.x; vector randvec4 = normalize(set(random(xmaxgridpos,160),0,random(zmaxgridpos,1600)))*freq.x; vector g1 = pos-set(xmingridpos,0,zmingridpos); //calculate the distance between the point in question and the grid corner vector g2 = pos-set(xmingridpos,0,zmaxgridpos); vector g3 = pos-set(xmaxgridpos,0,zmingridpos); vector g4 = pos-set(xmaxgridpos,0,zmaxgridpos); float res1 = dot(g1,randvec1); //dot product between the distance vector and the random vector float res2 = dot(g2,randvec2); float res3 = dot(g3,randvec3); float res4 = dot(g4,randvec4); float u=fit(pos.x%freq.x,0,freq.x,0,1); //where the point is in relation to the corners of the grid float v=fit(pos.z%freq.z,0,freq.z,0,1); float temp1 = lerp(res2 ,res1,v); // interpolate the values float temp2 = lerp(res4 ,res3,v); float result = lerp(temp2,temp1,u); return result; } I just wanted the x and z coordinates for simplicity. I'm reading through some tutorials (http://flafla2.github.io/2014/08/09/perlinnoise.html), but he implements a variation (i believe the simplex noise). I just tried to copy what is said in the introduction in the article above. As I have zero clue about what to do, and if anyone is interested, I would like some insight to understand the inner workings of the perlin noise Kind regards, Bajt
  6. Field Force based on RBD Simulation?

    The initial Purpose of this setup was to simulate tension in breaking wood. I need a boat crashing into a cliff, but right now it just falls apart. I wanted to do a setup, where houdini detects where the shards angular velocity changes, and apply force there to intensify the effect. But now I fear that i didnt think this through, because as you said, if there is force applied where the velocity changes, it will accelerate in a cyclic fashion.
  7. Hello, I'm fairly new to houdini, and just learning what you can achieve with it. I need a Forcefield based on the change of velocity in RBD objects. I tried to isolate the points with changing velocity with a VOPSOP and a Timeshift comparing the velocities (the same technique used in the waterfall tutorial on vimeo). It works well, but i thought about applying a force field with the simulated and isolated objects as a source, but that doesnt seem to work. The force field doesnt follow the simulation. I#ve attatched a file to show you what i mean exactly: RBD_Force_field.hipnc