MiikaHweb Blogi -> Blender (Sivu 2)

Today I was testing Blender's new camera tracking functionality together with Dynamic Paint wave simulator on soc-2011-salad branch.

I had some issues with tracking system, and eventually I had to use 2D markers instead of 3D ones and that required lots of tweaking. But even though tracking tools are still in early development, it worked very well after all. With this development pace I can just wonder what one can do with it by the end of summer. :)

Here is the final render:


What you see here is a Suzanne monkey head added to a real footage. Water particles and wave visibility could still use some tweaking, but overall I'm quite happy with the result.



I also noticed a nice Dynamic Paint waves test by CristobalAtria:

Last week I was checking my iWave implementation from February. As you may remember it had quite strange issues: it kept emitting waves way too long after the obstacle had moved away, and sometimes waves seemed to move in wrong direction.

Finally I decided to implement another 2D wave algorithm instead. This time it's based on "Height Field Fluids" slides by Matthias Müller-Fischer. With some modifications it now works on mesh objects and is even compatible with new vertex surfaces.

Basic implementation is now ready and committed to soc-2011-carrot branch. It may still need some tweaking but unless something critical appears this should be about finished.

Here is a video showing a couple of test scenes:



If you want to try it yourself, here is a sample .blend file for carrot branch revisions 38044 and later.
Download .blend

Dynamic Paint "effects" system is now back in latest version (r37848 or later) of soc-2011-carrot branch. Paint effects is a special option for paint surfaces that generates animated movement for wet paint.

Now it also works with vertex surfaces and has some improvements too. One of the largest visible update is that you can now use Blender's "force fields" to control dripping direction. So it's no longer limited to negative z-axis only. ;p Color mixing behavior is also improved.

Check out this video of an animated point force dragging paint around:

Vertex group painting that I was experimenting with in January, is now finally available for download. I committed it to soc-2011-carrot branch earlier today, so just get a Carrot branch build at revision 37622 or later. You can get Windows builds from MiikaHweb Blender Builds section.


I also uploaded two example .blend files you can use to try out Dynamic Paint's new realtime vertex painting functionality.

This demo shows how to use Dynamic Paint's vertex level color and displace:

Download .blend

This demo shows how to use vertex weight groups to control particle hair length. This one is very similar to the "Grass Worm" video I posted earlier.

Download .blend


One critical component is still missing though. Currently there is really no proper way to render vertex colors in Blender. It's only possible to render one layer at time and only use it as diffuse color. :(
That's something I'm planning to improve later this summer.

MiikaHweb Blender Builds system is now updated.

I wrote some scripts that take care of compiling and uploading new builds so maintaining them is now just matter of few clicks. This means more often updated builds.

I'm now building branches too. So far only BMesh and "paged-particles". But I'm going to add more when new somewhat regularly updated ones emerge.

This also means I'm going to do regular Windows builds for GSoC 2011 branches too, when they are available.

Lately I have been tweaking and testing iWave simulator to achieve more realistic results. Sadly it seems like the more tests I do, more strange behavior I encounter. :)

But realistic or not. Results are at least very interesting, allowing yet another new way for Blender objects to interact. So of course I will finish this project and improve it as much as possible. One new thing is foam generation. When enabled, it automatically generates foam on wave highpoints and is very good for boat wake/trail foam.


Notice a "bug" how those small waves are moving in the wrong direction in the beginning. Let's consider it as engine turbulence. ;)

Basic water movement (ambient waves) are generated using Blender's new Ocean Simulator modifier, boat wakes using iWave.


Because adding new 2D-simulators to Dynamic Paint is quite easy it's likely that I will implement an alternative more accurate wave simulator sometime in the future.

Edit: An alternative wave algorithm (not iwave :x), has been added to Dynamic Paint instead.

A couple of days ago I was playing with Blender ocean simulator modifier. While it's able to generate realistic wave motion, it's not able to interact with other objects.

Then I got an idea: what if I integrated a simple wave simulator with Dynamic paint!

So I ran across iWave algorithm by Jerry Tessendorf. I also discussed this with ZanQdo (Daniel Salazar) who was already implementing iWave for Blender through Python. We agreed that Dynamic Paint could be the best way to go, because it allows easy object interaction and is able to output textures as well as displacement.

iWave is a simple algorithm for simulating 2D water surface ripples/waves and their interaction with obstacles.


Now after a few days I already have a very basic iWave integration:

What you see here is an iWave surface interacting with Blender objects via Dynamic Paint. You should also note that it's just a normal mapped plane, so it's very fast to render!


Unfortunately, there is still lots of work to do before I can release a public test version... :s

Edit: An alternative wave algorithm, has been added to Dynamic Paint instead.

Recently I have been working to improve Dynamic Paint functionality and allow painless Ptex (Per-Face Texture Mapping) integration in the future.

This next step is _vertex painting_. Basically you'll be able to select canvas output type. Available options will be vertex, Ptex and image output (current dp). Vertex output allows you to paint vertex colors, vertex groups and displaces.

Operating on vertex level makes things easier in many ways. First of all you don't have to unwrap any UV data or load image sequence textures to make it work. It's just clicking bake and seeing the results. Even displace will happen directly by the Dynamic Paint modifier.

Negative things compared to image textures are limited resolution and rendering options. That's why vertex stuff isn't going to replace current Dynamic Paint but to be an alternative way. Hopefully Ptex will be the ultimate Dynamic Paint solution. :)


I made a small demo of vertex group/weight painting. A grass worm.

In that video grass particle length is defined by a Dynamic Paint generated vertex group.


Please note that this is still in very early stage of development. You shouldn't expect any kind of test versions for several weeks.

I figured I'd post some cool Dynamic Paint videos I've seen on YouTube/Vimeo. :)


Tyre burnout skid marks by blazraidr:



Fire burning away skin, also by blazraidr:



Cool fluid drip effect (Dynamic Paint texturing guided by fluid particles) by edi:



Dripping paint on a simulated cloth, by TheBlendervideos:





In case someone had trouble compiling Dynamic Paint, I recently uploaded v1.18 that mainly fixes compile errors on latest SVN revisions (no new functionality).
I also posted the patch to Blender tracker. Hopefully someone is able to review it before they start accepting new features. :x

Yesterday I found an easy way to report Dynamic Paint status without console. Just show the result within the ui - like many other Blender parts have done for a while. Yet, I never figured it's possible to do that. :x

Now, when baking is done you get a new text field below the bake button that tells you what happened. On a successful bake it just reports "Bake complete! (Time: -)". In case of an error, like missing UV data or no paint objects in scene, you'll get an error message that tells you what's wrong.

Of course all this info has always been visible at console, but now it's easily visible within the ui! Still can't believe I didn't figure this out earlier. x_X

EDIT: I also added Blender 2.5x style error and warning messages in case of a non-successful bake.