anthonyblanchettepotvin

Hi everyone, I'm trying to simulate paper using vellum and I can't get the friction and drag right. I kind of got the result I wanted, though I still don't understand those values. By "those values", I mean static and dynamic friction and normal and tangent drag. I'm a really visual person and there's no example or graph that show's how this works on the Houdini documentation, so I thought that maybe one of you would be able to explain it to me ? Thank you.

Hi people, I'm trying out Vellum in Houdini and I was wondering how mass works. I noticed that the mass is a point attribute. That said, if I want to know the total mass of the object, do I need calculate the sum of all the points ? Thank you.

There's a simple example of what is my problem. editableFollowingCurve.zip

Hello guys, Is there a way to create to dynamically create curve point custom handles ? I know I can create a simple curve in HDA and export the curve handle to the HDA, but I can't animate the curve position and edit the curve after. The curve node doesn't take account of the transform node, so it's a bit wierd to modify the points of the curve when the result is 100 meters away. Any help would be appreciated !

Hi @Maurits, Are you able to explain me a bit what the code does ? I have a decent background in programming, but with the lack of comments, I don't really know what variables like cpn, cpo, cn and co does. I would like to learn how to create custom handles like you did. So, I'm trying to understand what you did. It would be very appreciated. Thank you !

Ok ! That's all I need to know. Thank you guys !

Hello guys, I am wondering if it's a good or a bad idea to use Python scripts in my HDAs ? Thank you !

So, here's a quick update. I managed to format the string within my Attribute Wrangle node. I created a detail attribute called coordinates that I can read from within the Coordinates parameter of the Curve node using an expression function called details which "returns the string value of a detail attribute". At this point, I can see my curve and I can change its length and number of points dynamically, which is awesome ! But, when I select the Curve node and try to edit the points, the only this I can do is insert a point. As soon as I insert a point, the new point appears in the Coordinates parameter and my expression function disappear to show its result. That said, I can't change the length and the number of points anymore. Before : After : At this point, I really don't know what to do. If something could help me with this issue, it would be awesome !

Hi, I wonder if it's possible to initialize a curve from a line and be able to modify the curve from the Curve node. I'll explain what I'm doing right now. Of course, it doesn't work, but I'm sure it will help you to understand what is my goal. Fist, I have a Null node called curve_setup. This node contains parameters that controls my line. So, the length of the line and the number of points on the line. Next, I have an Attribute Wrangler node. This node creates the line using the parameters in the curve_setup. At this point, I did some research on the Curve node and the documentation says that I can "use a space-separated list of coordinates in this field to specify points". Then, there's a list of different format to specify different points. There's one format that got my attention. It's the Pn format which "copy the coordinates of point number n in the input geometry". So, I said to myself : "Is there a way to copy the coordinates of all the points of my previously created line in the coordinates of my curve ?". Then I did more research. I learned that the Coordinates parameter is a string, so I have to use expression functions. That said, I learned that there is a expression function called pointlist that returns a "space-separated list of point numbers". Since this function returns something like this : "0 1 2 3 4 5 6 7 8 9", I though that I could format the string and add a "P" in front of every number in the list. Since Pn "copy the coordinates of point number n in the input geometry", It would create a curve based on the line I created earlier and since I can see those points from the Curve node, I would be able to modify those points using the Curve node handle. Now, I just need to learn how to format the string within the Coordinates parameter of the Curve node.

Not really. The curve is built-in the HDA. I'll explain why. Basically, the HDA is a pike. But, it's a special pike. It's tip can be extended along a curve. So, I needed the curve to start at the tip of pike. The purpose of the pike is to be animated along a path and at the end of it's course, the tip must extend using the curve. The curve will need to go around objects and characters, so that why did a built in curve that follows the object everywhere. But now, I want to be able to modify that curve anywhere the pike is to have a clear look at where the curve will go. Because, If I use a user defined path created at the origin while my pike is at, let's say, 10, 0, 20. It's hard to modify the path and look at the result which is the pike, which is 10 miles away. I'm pretty sure it's not clear, but I can try to send you the HIP file so you can understand better.

Hello guys, I have a simple question. It is possible to initialize a curve in an HDA and give the user the possibility to edit that curve without jumping into the HDA, select the curve node and modify it ? If so, how may do this ? Thank you !

Thanks guys ! I think that would be enough to make it work.

Hello, I'm working on a school project and I need to align a curve to the end of a line both in position and rotation. My goal is to be able to create a curve, anywhere in the scene, and snap the start of the said curve (point 0) to the end of the line. The end of the line is extracted with a carve node on the line itself, so nothing complicated here. So far, I've been able to simply copy the curve onto the end of the line, but it only work with the position of the curve, not the rotation. It's important to note that I purposely created the curve in -Z axis. I know it will work if my curve is properly aligned in the Z axis, but I want my asset to be the most fail-safe possible. That said, It would be very appreciated if someone could help me with this issue. There is a attachment showing my current network and what it looks like in the Scene View. Thank you !