Trollywood

Going back to my home country to talk about Bridgerton s03 and how to be efficient in Houdini at Trollywood. Come see me! 

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Inflate an Object in Vellum

In this quick video, I'm showing you how to inflate an object in Vellum. I got his question a while back, so I decided to make a tutorial about it. This method also work for whatever constraint properties you want to animate.

How to Create Custom Constraints for Your Ragdolls in VEX

In this tutorial I’m talking about how to create custom constraints in VEX for your ragdoll sim. Unfortunately I got over my 10 minutes limit, but there was just so much stuff that I needed to squeeze in.

It’s a bit technical so you probably need to have some basic understanding of VEX and ragdolls to be able to appreciate it.

If you don’t want to write the code yourself you can copy it from here:

int number_of_agents=npoints(1)-1;

string left_hand;
string right_hand;

int pointID_left;
int pointID_right;

for(int i=0; i<number_of_agents;i++){

left_hand=sprintf("mocapbiped3_%d/LeftFingerBase_To_LeftHandIndex1",i);
right_hand=sprintf("mocapbiped3_%d/RightFingerBase_To_RightHandIndex1",i+1);

   

    pointID_left=findattribval(0,"point", "name", left_hand,0);
    pointID_right=findattribval(0,"point", "name", right_hand,0);  

 

    int primID=addprim(0,"polyline", pointID_left, pointID_right);
    setprimattrib(0,"constraint_name", primID, "Pin","set");

}

Emit Particles from Geometry Intersections

In this tutorial I’m showing how you can use the Intersection Analysis tool to create emitters whenever you have geometry that intersect.

Basic Material Style Sheets in Houdini

There seems to be a lot of confusion around Material Style Sheets in Houdini so I decided to make a very basic tutorial about it.

Quick Tip: Using the built in mocap biped 3 for crowds

I got some questions about how to use Houdini's built in mocap biped 3 instead of an fbx for your crowds so I decided to make a quick video about it.

Create Arrays Containing the Vertices for Each Primitive

I got a question about how you could create an array out of four points for each primitive in one of the comments so I thought that I make a quick example.

So in this scene I'm reading every vertex for each primitive, put them in an array, move the box,  read them back and then add a point at the original position. It looks like this.

Make sure that your Attribute VOPS are running over primitives.

Inside the first VOP I'm using a For Loop and the numvtx (which is the number of verticies that the current primitive has) to drive how many time it will loop. I'm then using an Import Vertex Attribute with the current element index to pick up the position of the vertices. Lastly I'm appending them to an array. As we've selected that we are running over Primitives this will create an array for each Primitive.

To read it back is very easy. Just make sure that you are running over Primitives here as well. After that you can just use an for each node to step through your arrays. 

Hope that you will find this useful, The project file can be downloaded from here: Project File

HeightFields for Crowds

In this tutorial I show how you can use heightFields to speed up crowds with terrain adaptation.

Crowd Basics 2: The Transition Graph

Part 2 in my Crowd Basic Series. This time about transitions with the help of the transition graph. You probably want to check out part 1 as well if you are new to crowds in Houdini. 

Crowd Basics 1: Locomotion And Foot Locking

In this video I'm talking about some basic, but important crowd concepts that often seem to be forgotten.

XSI To Houdini 4: From States to Streams

In this tutorial I'm showing how you could set up something similar to XSI's states in Houdini through POP streams and a SOP Solver.

I realized after that I've recorded the tutorial that I didn't show the DOP set-up that I'm starting out with so I made a screen grab. As you can see it's very basic. 

Download Scene File

String Attributes Through Stamping in a Font SOP

I'm showing how to get the Font SOP to type out values from a string attribute when you are using stamp. Maybe not the most exciting subject, but it can be quite useful.

If it's hard to read in the video, the expression I'm typing is the following:

`points("../assemble1", stamp("../copy1", "pName",0), "name")` Don't forget the ` in the beginning and end.

XSI To Houdini: Find Point Neighbours

In this tutorial I'm showing the Houdini version of "Get Closest Points". I'm talking about how to look for neighbours in a point cloud and either average out the values or loop though them to do a specific operation. I also talk briefly about the Houdini equivalent of Get/Set Data and Rescale.

If there are any particular ICE nodes that you would like to have a tutorials for, let me know.    

Follow up to XSI -> Houdini and locations

I got some questions after my XSI to Houdini tutorial about the closest location on a geometry from people that didn’t really understand how “xyzdist” could be the same thing as "get closest location" so I thought that I better do a follow up. The big difference is that in XSI a location is just one variable and in Houdini it’s 2 (the Primitive and the uv on that primitive). In XSI you use a ‘Get Data’ node to extract data from that location and in Houdini you use a ‘Primitive Attribute’. I hope that clear things up.

Houdini Quick Tip: Merge messes with your orientations

Just a quick tip about why and how to avoid that Houdini sometimes messes with your orientations when you are merging things together. Hope that you'll find it useful.

XSI to Houdini: Find the Closest Location

In this tutorial I'm showing the Houdini VOP version of Get Closest Location in XSI.