Render-time Up Resing of Volumes / Volumetric Data

I have been thinking about some posts on here, but couldn't really squeeze out any time for it. Been quite busy with work.

Anyways, I have been working on a tool which scales the resolution of the volumes at render time.

I'm still working on this tool, trying to refine the whole procedure / logic and trying to get a higher fidelity in terms of movement, base shape preservation etc.

Here's a test using a simple low res smoke sim:

Gridless Advection methods

Here's an implementation of Gridless Advection methods described in the Volumetric methods siggraph course by Jerry Tessendorf.

The implementation is done in houdini.

Course has some great insights on volumetric methods followed by various vfx facilities on production.

Though its a process which happens at rendertime, I implemented it in SOPs to get interactive feedback (Though same/similar setup could also be used with volume procedurals).

Following are the two screen shots of a simple sphere with and without GA applied to it (Just one iteration. My laptop starts to freak out after that   :D). The resolution of volumes is 200 (uniform divisions).

The setup could also be used within a SOP solver to get all sorts of interesting results 

with finer details.

The velocity field (the advecting field used here) is created by using very low res particle sim.

Will be posting some other tests soon.

Naiad-Houdini reel

This is my reel for Naiad-Houdini specific works.



I would like to thank:

Marcus Nordenstam and Exotic matter team for their generous support.


Alejandro, Julien and Jeff for contributing their insights and knowledge with Volumetric effects.
people at odforce and exotic matter forums.


Cheers.

some hush hush work..Masters project.

I feel as if i have been reborn..last few weeks were really busy and exhausting. But they have been quite productive nonetheless.
I have been experimenting to my heart's content and the results are looking good.
Following are some of the images from each of the shots I worked on (just 3 of them.)





I will be posting the link for the video (and the "how to" details etc) in some time..
need to touch up somethings..should be done in few more days :)

Elementary....

I have been working on Naiad for some time now and testing few things on the go.
As of now, most of the tests have similar principles as I need to check all the possibilities for one of my projects but as soon as I can get over with this, I guess I have all the time to work on some better/interesting effects.

This is a test where a water character is running on a pavement and sort of disappears from the scene towards the end. At the moment I have just stopped the emission at a particular frame (as an alternative) but I guess I could make it behave in a different way for that.


I guess I'm slacking off..the idea of writing another post doesn't really excite me for now(lots of work left)..so thought would probably add in another naiad test here..

Naiad..Meshed and Rendered ..

In this setup the body is levitating in air mimicking the movements of an animated torus and spills only if the velocity is greater than a threshold. Simulation done in Naiad.

Here's a test with a meshed out render.
Rendered out with Houdini's Mantra renderer.


The Catmull-Rom filter gave me best results for this. I have started to prefer it over the gaussian 2x2 which slightly smoothed out/blurs my renders a bit.