Here’s a quick update. As part of my involvement in FOHR (webpage, facebook), I’ve developed a TechnoCrane 50. This will be used for creating the animatic of a teaser shot that’s under development.

The animation rig is based on the actual specs of the real TechnoCrane 50. It can automatically limit rotations and the extension of the arm on both velocity and acceleration.

When these limits are crossed the rig will not move any faster than is possible and the blue and green indicators (image above) turn read and show how many degrees or meters your animation is overshooting the physically possible values. Of course the indicators can be turned off as a whole or individually to remove clutter from the view port. This is also possible for the visualization of the rig itself and the animation handles.

Building in the limits functionality was a fun little project and as in many occasions, CHOPS are your friend. It basically works by first using the Slope CHOP to measure velocity or acceleration (first or second derivative using basic differentiation). Once you have the velocity or acceleration is easy to limit the values. These limited values can be turned back into positions/rotations using the Area CHOP (integration). Using the Export CHOP its easy to push the limited values back to the parameters for translation or rotation. This all works really well and fast as well .

Another functionality I built in was a subject tracking camera head. The tool has a slider that allows the animator to blend between animated camera head rotations or automatically tracking the subject.

Animation can be done in the viewport using the animation handles (see image above) or using the parameters of the tool (see image below).

The limits on the rig are all parameter based so it is possible to change the physical properties of the rig (perhaps setting lower limits to force more gentle moves).

Anyway, it was another fun little tool to build (though not as ‘glamorous’ as water tools).

Cheers,

Erik

Hi,

I’ve had some ‘short’ break before where I didn’t get to updating the blog for a few weeks or so. This time it has been months since my last update.

This doesn’t mean I haven’t been doing anything though. In fact, I’ve been really busy doing some really cool stuff.

I’ve been working on a long project (far from over yet) about which, I can’t really say much However, I can mention that one of the things, I’ve worked on is a high level Python based development toolkit for building tools in Houdini. The most visible part of that toolkit is a user interface toolkit that makes it very easy to develop complex user interfaces for HDA’s, that is heavily inspired on Apple’s Cocoa development frameworks.

This started off as a fairly lightweight wrapper around the nastiest bits of parameter interface coding in Houdini (including wrapping bugs and things I think are just weird, like multi parms and all their behavior). It quickly grew into a full fledged high level UI toolkit and extended into generic, MVC (Model View Controller) framework code (Protocols, Responders, Notifications, Delegates, DataSources, …).

Anyway, it was a cool opportunity to exercise the Python coding muscles and get deeper into Python development in Houdini than I’d ever would have otherwise. At the same time tool development will be more fun than ever using these new shiny toolkits

Another thing I worked on with an ‘extended subset’ of the ‘dog morph team‘, was providing a pile of vfx shots for: The Lost Christmas. Looking at the IMDB page, I just noticed that I haven’t even added myself to the list of vfx crew yet. We as a team added a lot of virtual ice and snow to many shots, personally, I mostly focussed on communication with our direct client: FilmGate and vfx supervision of our team.

In short plenty of cool stuff happening. In the coming period I’ll be working on my water tools again, which I’m really excited about as that’s what my Houdini adventures started with.

And with a little (well… probably better to say big pile) of luck, I’ll find some time to finalize that Tron sequence as well in the coming months, I was already quite far in getting all the technicalities to work, so really should finish it).

To wrap up… there’s also some other developments, I’m really happy with, going on about which, I really can’t talk until it goes public. Anyway, it’s good to ‘be back in the blog’, with a bit of luck I’ll be posting the last of the ‘dog morph’ posts somewhere next week.

Cheers,

Erik

Now the exhaust wall stuff is done and made into a tool, attention has shifted back to the explosion animation and simulation. By now all the major systems for animating and hand-over to simulation are in place.

Let me start by showing you a test animation for that I’ve rendered out. I did a very quick multi-pass comp on the render to attenuate reflections a bit and add some glows. The animation is rendered at 8 times slow motion.

View in high resolution: H264.

(more…)

Here’s another update on the ‘exhaust wall’ part of the ‘derezzing’ sequence. As I was getting the exhaust wall network up to a level I was satisfied with, I figured, why not make it a tool and apply it to the red bike easily. That seemed like a jolly good idea, so I quickly got to work.

First, however, let me show the results coming out of a test render of my new tool (8 times, slow motion). Note that this render focusses completely on the exhaust walls. The background is still a placeholder, so is the grid (too low res texture), and the red cycle animation definitely needs quite some animation love, especially when it hits the ground. It’s also the ‘raw’ render output, with only sRGB applied. But…. with all those disclaimers:

View in high resolution: H264.

(more…)

As I’m wrapping up another fun project, it is time for some long overdue updates on my blog.

I still haven’t found the time/energy to make that ‘build a wave animation’ screen capture. This is still very much in the planning but I’m going to stop promising it on a concrete schedule as more work is coming up shortly and there is only so much time in a day.

In the mean time, I’ve got some really cool tool development just about to get started, extending my efforts in water/object interactions and bubble advection so far, into a toolset that is able to create some really nice looking splashes and foam effects (both above, on and below the water surface). I’ll be adding the same spray and foam functionality to the breaking wave and ocean displacement tools as well, which should be really cool!

So, plenty to cool stuff on its way!

With a bit of luck I’ll find more time to keep updating the blog in the coming weeks than I have the last month and a half.

Cheers,

Erik

Hi,

I’m proud to be able to say now that SideFX‘s Jeff Wagner will be demoing my wave tools as part of his ‘Advanced VFX In Houdini’ master classes at FMX this year!

(more…)

Here’s another sneak preview on a big update coming up soon. The surfacing part of the DEFBreakingWave HDA is all but at version 1.0 (at least at beta level). I’m doing the ‘final’ touches on the UI to make it more streamlined and logical.

(more…)

Hi,

Phew! It has been a LOOOOOONG time coming, but I’m finally ready to update on the new Gerstner displacement, as implemented within the breaking wave tool. Most of the time it took between the previous update (the sneak preview) had to do with a completely new addition to the displacement of the lip of the wave, which required some dynamic simulation stuff using a Sop Solver in DOP’s.

I’ve now fully integrated the Gerstner logic into the wave system. The main thing I’ve got more work on is the UI. The Gerstner calcs can get you really nice results but the parameters are very sensitive and have strong relationships with each other. This means that sometimes changing a value by a small amount can have really big impact on the final result. By experience I’m starting to get a feel on what relationships between parameters will lead to most natural results so I can build in those relationships into the UI, which will greatly help in setting up nice looking wave displacements quickly.

(more…)

Before I get into the displacement functionality of the wave tool, I’d like to take a little time to go through some foundation work I did to improve displacements.

Up till now I was using regular noise functions to create the displacement of the ocean surface. This looks kind of ok as long as you don’t look to closely at it. The problem with regular noise functions is that the wave forms they generate have similar roundness at the top and the trough of the waves. Real waves, however tend to be ‘sharper’ at their tops and rounder at the troughs. So I thought, I’d better fix that before I continue with the displacement functionality of the wave tool.

(more…)

Shading time… After a few ‘false starts’ it is time to go through the shading side of the wave system.

Before I get into the shader itself, I thought I’d be a good idea to quickly recap how the UV’s of the wave are integrated into the UV space of the ocean surface. Luckily, I have already posted those details on this here: Another refactoring.

(more…)