# TobiasSteiner

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1. ## Wobble (rotate) points on axis using VEX

Hi guys, I've been giving VEX a go recently and I've hit a block in something I'm trying to achieve. I'd like to take a set of points from a scatter node and wobble or wiggle each of them randomly on a given axis (Y) over time. As an expression this is as easy as sin(time * #) in the rotation transform for a desired axis. This doesn't work in VEX as everyone knows. I did find a lot of reference on matrix and quaternion functions in VEX and this seems like the way it should be done. It looks pretty complicated though for something as simple as wobbling a point on an axis. I know VEX works with radians only. Anyway, I'm sort of stuck. Any help would be appreciated. Thank you!
2. ## 3D Generalist - Demo Reel

Hello! I would be grateful to be considered for any opportunity to work with some of you on a project. Please review my reel link below. I am the sole proprietor of FrameHaus LLC based in Las Vegas, NV and routinely work on remote projects of all kinds. I look forward to hearing from some of you soon! https://vimeo.com/217558652 Warmest regards, Tobias
3. ## Wobble (rotate) points on axis using VEX

Exactly. That was the part that I wasn't seeing at first. Houdini thinking is a bit different in certain ways than with other 3D apps. The gotcha is that the scatter node does not create point normals so you have to recreate them afterwards. I added the file here in case anyone ever comes across this problem and wants the solution. VEX_Axis_Motion2.hiplc
4. ## Wobble (rotate) points on axis using VEX

That was the initial code. Drop the updated vex on a point wrangle after a scatter then feed that into a copy of some small grids. You'll see it work then.
5. ## Wobble (rotate) points on axis using VEX

I got it!!! Stay tuned. Cleaning up then I'll share. Here it is: vector normal = normalize({0, 0, 1}); @N = normal; @N.y += .1 * sin(@Time + @ptnum); @a= fit01(rand(@ptnum), ch('slowest'), ch('fastest')); f@b = ch('speed_rate'); @c = (@a * @b); @P.x = (@c * @Frame); This does EXACTLY what I was trying to do. I'll mess around with it some more to get user controls added for specifying axis of direction and wobble. Thank you guys for your help. It actually helped me come up with the solution ultimately. Grateful. You rock!
6. ## Wobble (rotate) points on axis using VEX

Actually that's almost it but not quite. Think of an aeroplane that wobbles slightly on its X rotation axis while it's flying down the X position axis. A slalom is more like a sine along the Z position axis with banking on the X rotation axis while moving down the X position axis. I think I got that right. But the goal is to do this in VEX. No solvers. No VOPS. p.s. Here's the start of the VEX that gets the points moving at "random" speeds along a chosen axis with user controlled speed. Part B of this setup is to get those same points to wobble in their rotation axis of travel. @a= fit01(rand(@ptnum), ch('slowest'), ch('fastest')); f@b = ch('speed_rate'); @c = (@a * @b); @P.x = (@c * @Frame);
7. ## H16 lags

Just tested 16.0.537. Still crappy UI performance if trying to use two monitors. Ugh, I'm so bummed out about this release. Looks like I won't be getting any use out of this release until I can get my hands on a wicked expensive video card. SESI is really crapping on my world right now. Really took the wind out of my sails.
8. ## Wobble (rotate) points on axis using VEX

Thank you. I'm really just trying to make each point wobble randomly on a chosen rotation axis. Think a flock of birds gliding in the X direction and each bird wobbles slightly on its X rotation axis in a sine range of 10 degrees or so. Birds, planes, or pigs....whatever the flavor.
9. ## Wobble (rotate) points on axis using VEX

Yeah it would useful for many situations. There has to be a simpler way than what I've come across so far.
10. ## Mantra Render - Hide Voronoi Fracture Cracks?

Working on a project that is just a simple break away of a fractured model. Problem is that Mantra renders all the cracks in the shape before they are pulled apart. Rendering the same scene in other renderers like Arnold Render does not yield this problem. The shape is not cracked before it it pulled apart which is the desired effect. Anyone know why this is not the case in Mantra? Houdini 15.5, latest Arnold render.
11. ## Mantra Render - Hide Voronoi Fracture Cracks?

Good tip regarding using the Material Shader Builder as an alternative. I will explore that more thank you. :-) Cd is not shown in the spreadsheet in this scene for the sphere object. Checked all tabs (point, verts, primitives, and details) prior to posting the reply and then checked again after your comment. The checkbox you're referring to must be "visualize pieces" and checking this box on is what creates the Cd attribute. However, this was never the case in the original problem presented. None the less, the Cd attribute is clearly "hidden" behind the scenes in the case where the "visualize pieces" is unchecked and is removable by.... ....using the Clean OR the Attribute Delete SOP. Each method achieves the same result to no harm or foul. The joy of throwing the knife at the same target in a thousand different ways. - Houdini
12. ## Mantra Render - Hide Voronoi Fracture Cracks?

Just for the curious. Here's the same two frames rendered in Arnold Render for Houdini. Each rendered in 6 seconds. The Mantra renders you saw in the previous post were 7 seconds (first frame) and 15 seconds (second frame). Same light type, position, and intensity. Exposure could be bumped a bit in the Arnold render but I think this shows how good of a render engine Arnold is. Not meant to be a brand debate post. Just sharing for those out there that might be curious and do not use Arnold.
13. ## Mantra Render - Hide Voronoi Fracture Cracks?

That's exactly what it was. This is an extra step in the process though in terms of using Mantra. There was nothing that jumped out and said this would be an issue. The Cd attributed isn't even shown on the spreadsheet after the fracture process. This seems a good candidate for usage improvement. Added a "Clean" node after the voronoi fracture node to remove Cd. Below is proof that your method worked for Mantra. Thank you for the suggestion!
14. ## Mantra Render - Hide Voronoi Fracture Cracks?

I don't think so. Tried adding normals to the post fractured GEO and that had no effect. See below. The fractured mess is the Mantra render. The perfect one is the Arnold render. Same scene. Same fractured sphere. 3rd photo showing breaking of same object is rendered in Arnold as well.
15. ## Bomb Force - AKA Volume Axis Force In All Directions On RBD Fractured Objects

Hi guys.I've been muckin' around in Houdini Indie 15.5 trying to get a very simple effect of pushing apart fractured geometry in all directions from the center (or any point of origin actually) and so far not very happy with the results.I've used the suggested “Magnet Force” method but to be honest this doesn't yield an acceptable result for a true bomb force effect. The various force nodes in Houdini seem to merely generate singular directional forces which is also not desired. I am aware of the method to set up a network of points or a point cloud of sorts that then all have a point force on them to drive dynamics however this is a convoluted and inefficient method at best.The desired result is very simple. If you are familiar with Maya which also uses Bullet dynamics, you may be familiar with the Volume Axis Force attribute which allows us to perform what I'm describing in one fell swoop. This is what I'd like to achieve in Houdini.Any insight into successfully achieving a true and accurate dynamic behavior of a bomb force would be greatly appreciated. Thank you kindly for your time and thoughts!
16. ## Bomb Force - AKA Volume Axis Force In All Directions On RBD Fractured Objects

Great ideas. I'll give this a crack....pun intended. Thanks!
17. ## Bomb Force - AKA Volume Axis Force In All Directions On RBD Fractured Objects

Understood. Thank you for the explanation. The effect I am trying to create with a falloff method is to introduce a slow cracking effect along selected regions just before the explosion force. I figured I could animate the region of influence paired with the scale force rising in order to achieve this.
18. ## Bomb Force - AKA Volume Axis Force In All Directions On RBD Fractured Objects

Quick question. If I use the "Enable Transform" option, am I suppose to be able to use the force field as shown in the viewer as a kind of falloff field? When I move this field far away from the fractured object it still effects it as though I did not move it at all. Even after toggling the "Set Always" option.
19. ## Bomb Force - AKA Volume Axis Force In All Directions On RBD Fractured Objects

Perfect! That made it all work just fine. Thank you so much!
20. ## Bomb Force - AKA Volume Axis Force In All Directions On RBD Fractured Objects

Thank you guys for the help. They all look pretty decent. This seemed like the most promising option but the attributes don't appear to animate in 15.5. I've tried keyframing Scale Force, Transforms (xyz position in the "enable transform" option), and uniform scale (if position in the center of the target object) but the value changes have no effect when keyframed. Bug or limitation of the asset?
21. ## compound curves, booleans, extrusion (AI, Alembic)

This is a pretty helpful thread. Thank you all for the information. I was also looking for solutions on this topic within Houdini. One thing that still isn't answered here however is the idea of true compound paths in Houdini on import. For example, in C4D when you import an AI file that has multiple curve paths in it they will all come in uniquely (as they should) and you have the option to "connect & delete" them all into one path object that C4D creates for further processes. This is done remarkably well and elegantly in C4D. I would like the same thing to occur in Houdini for things I'm working on, eg morphing curve paths. Is there a way to take the resulting paths generated from either an AI import or the Trace method and connect them together as one object? Join doesn't work. That just creates a mess. Thanks in advance for any insight into this.
22. ## Differential curve growth

Has anyone had any luck with this? I still haven't solved the issue.
23. ## Differential curve growth

Excellent point regarding the file share. It's attached now. The base template is the Houdini to Arnold Basic Studio setup I made to share freely from my website so if you don't have Arnold when opening it you'll need to create Mantra lights, shader, and render node. Growth Morph Wireframe.hiplc
24. ## Differential curve growth

No one has ANY idea at all???
25. ## Differential curve growth

Hi guys. I'm having some trouble getting shading to work on parts where growth is happening if I use a "WIRE" node on only a group that contains the effected area. If I don't use the wire node I'm able to use multiple shaders assigned by group. Any tips on how to get multiple shading assignments to work when inserting a wire node? Any help is much appreciated.
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