Pepakura Peugeot 206 WRC

Here's a more complicated Pepakura build. One with small pieces and curved surfaces.

1st Completed Pepakura Model

Here is the first completed Pepakura paper craft model. A little orange 'practice' car. A little paper craft car at first might not feel at home on a blog about visual effects, but the possibilities that Pepakura opens up is surely worth blogging about.

Pepakura (http://www.tamasoft.co.jp/pepakura-en/) is a program that lets you take 3D models and convert them in to paper craft models. It creates paper cutout templates with tabs and fold markings based on the facets of a polygonal 3d objects.

It seems like people have been using it for quite some time to create a base for Halo armor. Combined with a bit of fiberglass resin (or the recommended non toxic Aqua-Resin), you can build armor, weapons, and pretty much anything you can design in 3D. It takes a bit of work to get it to a finished product, but it's definitely cheaper than having a 3D printer.

Mental Ray Render Issue Solved!!

For the longest time, the Buggy model was plagued with render-crashes when rendered in Mental Ray. Originally it was thought to have been the heavy 2.5 million polygons in the model file, but even optimized down to a 500k poly model, it still exhibited the same crashes. It took a bit of sleuthing, but I've narrowed it down to the file textures used to drive the dirt maps.

The solution to the issue was to use memory mapped textures. From the Maya help file:

"...memory mapping is based on the concept that the image data on disk does not require decoding or data type conversion, but is available in the exact format that mental ray uses internally during rendering."

There is a utility that comes with Maya called "imf_copy". The utility is used for converting file textures to other supported formats, including one called '.map'. The '.map' format seems to run about the same size as an uncompressed .tif image.

I've tested a few renders after the conversion to .map textures, and mental ray hasn't spat one out yet. Going to rigorously test it under more memory intensive conditions (final gather + global illumination), but it's looking good.

Render crashing problem solved.

Mini Nissan SR20DET Valve Cover

What originally was an anisotropic shader test to recreate brushed metal/aluminum, expanded to become a modeling exercise as well as a test for the mia_roundcorners node. Also thrown on top in AE is depth of field via the Lens Blur filter, using a depthmap to drive the focal plane. There is also a small bit of chromatic abberation applied using The Foundry's Tinderbox2 plugin.

Notice where the NISSAN emblem characters meet the surface of the valve cover? That's where the mia_roundcorners node really provides that extra bit of detail.

Valve cover modeling workflow: Poly -> Sub'D -> Poly
Nissan text emblem: AI -> Beveled Poly

Test Composite

Here's the animation in it's rendered form before any roto work. Also working on integrating some Maya fluid dust plumes. Right click HERE and choose Save-As.

Animation Update

The wheels on the buggy now use a noise texture to operate the translate.Y channel, semi-automating the higher frequency bumps. It's so subtle that you hardly notice them at this distance.

Check it out HERE.

August 06, 2008 Update

Here's a rising dust test using Maya fluids. The background is a random car-related photo I took at the track. Feels like the fluid dust can use a volumetric lighting pass, as well as falling back to the ground after a certain time.

Download dust test clip HERE.

I also had an animation update as well, but all that's been updated is the wheels turning + power slides. I want to get the secondary animations in there as well before i post. I'm thinking about using a procedural pattern to affect the the wheel bumps.

Pumpkin Patch Playblast

We've shot several background plates for tests, and here's one with the buggy weaving around a pumpkin patch. Tracked in Boujou, rough animation in Maya.

There are issues with maya importing a scene with multiple layers of referenced files which still need to be worked out.

You can check out the clip HERE.

Buggy Manual Rig Test #1

Here's a test of the manual Buggy animation rig. The wheels rotate according to the forward translation of the global mover controller. This is done by the expression:

objectRotate = controllerTranslate * 2 * Pi * wheelRadius;

I found this expression in the "Maya: Professional Tips and Techniques" book by Lee Lanier. A great book for exactly what the title states. However, upon closer inspection, I noticed that the equation can be simplified to:

objectRotate = controllerTranslate * Pi * wheelDiameter;

Maybe it's a math thing where it's customary to state the radius, but it seems a little convoluted for my purposes. It's hard to see in the little blogger video window, so the download link is below.



Larger Size Video

Buggy Daylight Renders

Here are three different daylight renders for the buggy utilizing Mental Ray's Physical Sun and Sky rendering attribute. Here are a few other fixes that might not be as apparent.

- Consolidated all referenced geometry.
- Optimized a 253mb file down to a lean 187mb.
- Downsized most image maps by 1K (3K down to 2K, 2K down to 1K)
- Took out the color map for the tires in favor of a base color.

Also took out the white 'GoodYear' logo. The logo is still present in the bump map for the tire, but can't really be seen unless the camera pulls up close.

Rendering in Maya still crashes the software even with the optimization, but command line rendering works just fine. The images below are rendered at 1280x720, and takes about 6.5 to 7 minutes to render a frame on a dual Xeon 3.2ghz workstation.

I do realize the dirt on the tires is different than the dirt on the body. It will be fixed for the next update. Also to come, simple manual animation rig.

Dirt Tires on Buggy

Maya repeatedly crashes while trying to render the tires in the Studio Stage setup, so here's an image of the tires on the base buggy (pre-mentalRay paintjob). I chose to disable the bump mapping for the time being, since the baked version didn't seem want to work.

For the crashing part, my guess is that the Studio Stage scene file is extremely convoluted. The base buggy body panels were replaced with other referenced in updates such as the ZBrush-painted muddy panels. Next step is to consolidate all the referenced scenes into one solid scene file for the model of the buggy. After that, outdoor composite render alongside live action cars.

Tire Texture Update

The old UV's were dumped in favor of a single cylindrical map. The dirt is a layer texture consisting of a 3d Rock texture and a 3d fractal, with a map to control their coverage. The ribbed sidewall is applied via bump.

Decal Updates

Decal with bump mapped details applied to it.


Studio render with decal and no bump mapping.


Studio render with bump mapped decal.

Decal Placement

Couldn't find the utility to layer mental ray shaders, so I figured the next best thing. I duplicated the geometry of the door panel, made transparent (except for decal), and turned off any shadow casting properties. Then I moved the geometry up and out from the surface just enough to avoid the flickering from crashing geometry.

Tire Texture

Definitely a rough, but here's a texture test for the tire. Ignore the extremely reflective rim, the visible texture seams, and the 'Muddy Tire Co.' logo (which will be replaced with whatever we want).

Looks like it'll be beneficial to do the UV mapping before smoothing. Currently, I'm using a cylindrical unwrap for the modeled treads, and a planar map for the sidewalls. A single map should fix the texture seam issue.

Buggy Muddy Studio Render

All I could afford was to render this 720x405 sized still. Mental Ray seems to be having a little memory issue when trying to render this at 1920x1080.

Suspension tests are coming along as well. Trying to develop a physics based suspension rig, but for the test we might just have to go with a hand animated version.

Buggy: Muddier Body

Added the mud on to the bull bars, and slapped more mud on to the Buggy's front end. Also carved out the windshield wiper blade paths as well.

Working out a mental ray shader network that will allow a decal to be placed on the side panel, utilizing a difference UV set. Also to come, thickness and depth in mud via render-time displacements.

Buggy Muddy Body

The Buggy body with mud applied to the lower surfaces. Still needs integration with the rest of the model.

Workflow:
- Export from Maya as OBJ with UV map.
- Paint dirt weight maps in ZBrush.
- Plug in dirt weight map into mental ray car shader, or use a layer shader for non-mental ray shader surfaces.

Buggy Muddy Fender

Z-Brush's funky texture painting workflow was kicking my ass all week, but I finally gave it a roundhouse kick to the face. Used Z-Brush to place rough dirt maps, exported a black and white mask, and tweaked a small bit in Photoshop.

Rendered in Mental Ray, with the 'mi_car_paint_phen' shader and the mask as a dirt map. Dirt also has a light noise applied to the bump channel, and color of dirt is controlled in Maya.

Buggy Tires Update

The Buggy has been updated again with the windshield wipers in their folded-up position, and the tires have been smoothed out. Dirt map tests to come.

Updated Buggy with Wipers

Here's the lastest update on the Buggy. Front panel faceting fixed, wipers installed, and the color of the lights have been desaturated. Below it is a comparison with the previously more saturated version in low resolution.

Buggy Paint/Light Comparisons

Here are a few tests of the Buggy with 3 different paint jobs, and 2 different light colors.

Original:


Forest Green:


...and finally, the requested green-silver with blue lights.

Buggy Studio Render

Here's a studio lit version of the Buggy. The body uses a tweaked version of mental ray's built in metallic car paint shader. The tires are also low resolution stand-ins. The top left forward panel is showing some faceting near where the twist handle thing-a-ma-bob sits. Going to increase the resolution on that panel before the animation tests. Also, the shadow needs to be softened up a bit.

Buggy Preview

Here is a preview of the Buggy. New additions include smoothed front bull bar setup and cheater suspension arms, springs, etc. They're not physically correct, but add a little detail to the underside of the vehicle.

The logo on the side was just slapped on. Eventually it'll become a chrome emblem of sorts.