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Wednesday, January 9, 2013

Houdini Fracture Systems 1

So, it's after the winter holidays and it's time to get back to work full steam. Today was my first all-nighter in the labs and I have started with my Major project work. As the FX-TD on the project I have to take care of simulating fractures, RBD, smoke, dust and fire mainly.

At the moment I am developing a destruction system. I have started by develping a particle-based debris system. It is a very fundamental system that emit particles and instances various pieces of debris geometry on to individual particles from a debris library.  This is the output for tonight:

A particle based debris system

The first part of the development cycle was to create a debris system library. For this I pre-fracture the geometry using the Voronoi fractures. However the Voronoi fractures give a very uniform look as can be seen below.

Pre-fracturing with default Voronoi fractures

To counter this problem and to be able to have more variation in the look of the debris pieces, I used the paint SOP to scatter points. This gave me a lot of control on my pre-fracturing.

Painting destruction

With painting done, I could go into the parameters of the scatter SOP and play with the attribute bais and control how closely I wanted the scatter points to follow the paint. The pictures below show point scattering with attribute bias values of 0, 0.6 and 1. At 0, scatter completely ignores the colour attribute Cd and points are scattered as before. At 0.6, more points are scattered in the painted area, giving a tighter distribution of points. At 1, all the points are scattered in the painted area.

Attribute Bias = 0.0

Attribute Bais = 0.6


Attribute Bias = 1.0

After the operation I added a foreach SOP and a delete SOP, made a couple of adjustments and exported the geometry as .bgeos. This generated a debris library for me.

After the library was ready. I began developing a POP network. To the particles in this network, I instanced the geometry from the debris library. Here is a snapshot of the result of that process:

Debris geometry being instanced onto the particle system

That is all for today. I will take it further tomorrow and add some rotation to the particles. Then I would add this POP based debris system into a larger destruction system.

Saturday, December 8, 2012

The door to the Oval office - Update

So, after Ross's Nitpicking, I was able to get rid of a few more faces. I am down to 193 now. Let's see how it looks after texturing now.

Down to 193 faces
Ross you are such a stingy ass!

The door to the Oval office

Okay I realised that the last post was pretty useless for the purpose of getting critique, as I didn't really post any wire-frame. Also, after getting a couple of suggestions from the pros I worked a bit on it and was able to take the poly count to 206 (yeah, that's 200 polys less O_o). The visual result doesn't really look any different. I do have some doubts still though. I am not really sure about a couple of decisions I have made. I will need to consult with my resident modelling teacher Ross Hildick. You can check out his work here: Ross's Blog

So here are the wireframe images of the door.

This is the overall structure. This has 3 main parts, the outer frame, the inner frame and the door. This component has a total of 206 faces.

The doorway: 206 faces

This is how it looks from the back. I have deleted all the back-faces to keep the poly count down.

The back-side of the doorway

This is the outer frame, isolated. This piece has a total of 28 faces.

Outer frame, 28 faces

This is how it looks from the back.

Outer frame, back view

The inner door frame. I don't know if it can be further optimised as it has only 6 faces.

The inner frame

The door. This piece has a total of 112 faces. As you can see, it doesn't really have any depth to it. I am not sure if that is a good idea. I know that it exactly fits into the inner-frame and the player won't be opening it, but will it catch lighting properly, if it doesn't have any depth on the edges.

The door, 112 faces

The door-knob is another poly heavy piece. It has 60 polygons, but I can't really think of any way to make it lower than this and still retaining the shape.

Door-knob: Front view

Door-knob: Back view
That was a long post :p
Thanks in advance for any critique. Cheers!


Friday, December 7, 2012

Sony games Low-poly Modelling Testing

I have started with modelling for the Sony games project. I am just testing out a couple of things right now. Tonight I modelled a door to the room. This will, definitely, not be a part of my final submission, but I am just testing out low poly modelling. This door here has a total of 393 faces, including the knob, which I feel is a pretty decent number. Any more details on it will need to be put into the texturing stage. This was rendered using a quick renderMan setup. This is an 11 second render.

Low-poly door: model 393 faces, rendered with renderMan (11seconds)

Tuesday, December 4, 2012

Suddenly Debris!

To bring this night to an end I just created a little debris system in Houdini. this is for my project with Sony Games. This is a test debris system which I then imported into Maya as .fbx. Then I adjusted the geometry a bit, but as you can tell, I didn't spend much time on it (floaty pieces).

This was rendered using renderMan with the IBL. This is a 3 minute render with shading rate and pixel sample turned up way high.

Rendered using renderMan IBL
Next step would be to add more size variation to this and add other elements such as wood and metal pieces.

Off to bed now!

BURNNNNN!

For Ego, I have to do some effects which involve smoke simulation, so I started to play around with the pyroFX system in Houdini. Here is the result of that. This is the very basic smoke cloud that I created using the system. I have rendered it using the Mantra PBR renderer and the micro-polygon renderer. The result is more or less similar, but PBR took ~3 minutes and and the micropoly took roughly 20 minutes.

Smoke cloud rendered using PBR renderer

Smoke cloud rendered using the micro-polygon renderer
The smoke here is just using basic default values. I would be revisiting it in a couple of days where I will start tweaking it to control it's temperature, fuel, wind etc. Also, I will be attaching it to direct-able particles at some point to simulate debris system.

Basic render tests with renderMan


Tonight I am doing some render tests with renderMan for Ego. I started out with working on a cartoony character to test out the GI options in renderMan.

This little guy is called 'Dino' and is modelled by Ross Hildick. The model is not finished yet, but I annoyed him to give it to me for the tests. As you can see there are a couple of problems with it, but overall the result is pretty decent. This render took 18 seconds.

Dino rendered with rederMan

After this I moved on to this other scene, again modelled by Ross Hildick.

Break-in AO pass
I did a rough lighting pass of the scene that Ross lent me and came up with this final result:

Break-in beauty pass. render time: 1 minute 23 seconds

It is probably too dark and is definitley very patch lighting work, but I did this in a couple of hours as this was just a rough test. The render time for this is around 1 minute 23 seconds.

Will be working on a few more scenes in the coming days, so watch out :)

AND visit Ross's blog here.
He is an amazing modeller! We call him Ross 'Lightning-hands' Hildick as he models incredibly fast :p