Jordan Walsh

Amazing, thanks @Librarian!! I'll start working my way through it.

Here is the file showing my initial vex setup (adding @w to rotation), a bullet sim with Rotational stiffness = 0, which matches my vex setup. And a bullet sim with the Rotational Stiffness = 1 (default) that shows the difference in rotation. I would like to match the Rotational Stiffness = 1 with my vex setup. I hope that helps rotationalStiffness_vex.hip

Hi, I have a simple particle integrator for quick RBD pre-visualisation. I wanted to match what I would get from a bullet SIM with no collisions (basically just the initial forces, and gravity) but Rotational Stiffness is modifying the initial angular momentum of the bullet sim, causing the output of my integrator to be different (since Rotational Stiffness is defaulted to 1). Can someone help me add a rotational stiffness/inertial tensor stiffness calculation to my integrator in VEX? Thanks!

Use the Instancer LOP.. sop import the instance geo into LOPs then plug into input two of the Instance lop, object merge the points into the instance lop. Default settings will look for points internally and instance geo as input 2

While im here... you can also point to an extra file in the help like this: #icon: opdef:.?icon.png Unfortunate you cant do this with the Operator type Icon.. as changing name space or version of the HDA means you have to update the icon path too

Best way is to use VDB from Polys and use the surface SDF to find your surface location. the sdf will give you the distance to surface and you can use volume gradient to find the direction to surface. Works only on closed geo though... so get that poly cap working!

Well even if you "dont" use a shader, one is assigned by default, your colour just overides the diffuse colour of that shader. You might be able get something out of the standard set but its easier to assign a shader and set your AOV outputs inside. I dont think you can get a Cd export by default.... could be wrong

It should work fine, just use a bind export in you shader exporting to something like "rgbMatte" and hook up your colour attrib (dosnet have to be named colour, but must be what attrib name you have on your particles). Just make sure you have rgbMatte as one of your AOVs. The biggest problems you will come across are not matching up the names and data types properly, then you get black AOVs.

Point deform is pretty good at interpolating, id just give it a go! I would have to have a look at your scene if thats not a good option, which I cant do at the moment...

Sorry, havent looked at your file but... Cant you just select the base points of all the curves and point deform them to your surface and set the pintoanimation in sops before you send to the wire solver? That way you are feeding in a goal position to the base points on the curves and not relying on matching it up with other geo. For selecting the base point you can always use a for each loop and loop over each curve and pick the first point of the single curve

You can import a w attribute the same way as a v attrib. This is angular velocity that you can set in sops how ever you want. You can modify it in a sop solver or use a torque node to add rotational force. You can also set the orient attrib to set the inital rotation on the objects.

You can get the parmTuples included in a take with hou.takes.takes()[0].parmTuples() but I can see no way of getting the vale that is stored in the take, apart from setting to manual, change to that take, eval the parmTuple, put back to the original take, then update. Is there a nicer way to access the take parm value?

Cool stuff but seems like there is no wire collisions in there. In fact it makes no difference to have the wire solve in there at all! Any one found a way to get wire collisions in there while editing the geometry in the sop solver?

When fracturing just use packed fragments. This will give you exactly what you are looking for, centroids, transform matrix pre piece etc. You may want to have a look at the Transform Pieces sop too if you need to re apply the transforms to different geo. If you are using a timeblend and packed geo make sure you turn on "Shortest Path Transform Blending" to get correctly blended matrix transforms.

Just wondering what the most efficient way of rendering fog volumes with area lights inside them, like below. Seems raytracing is about twice as quick as pbr but I find it difficult to get rid of the noise in the very bright areas around the light. Anyone got any good trick for this type of thing?