Unity Archives - Digital Urban

Particles – 3dsMax and Lumion/Unity

Andy — Mon, 01 Sep 2014 10:43:24 +0000

Particle Flow is a versatile, powerful particle system for Autodesk’s 3ds Max. It employs an event-driven model, using a special dialog called Particle View, allowing you to combine individual operators that describe particle properties such as shape, speed, direction, and rotation over a period of time into groups called events. Each operator provides a set of parameters, many of which you can animate to change particle behaviour during the event. As the event transpires, Particle Flow continually evaluates each operator in the list and updates the particle system accordingly.

pFlow 3ds Max

To achieve more substantial changes in particle properties and behaviour, you can create a flow. The flow sends particles from event to event using tests, which let you wire events together in series. A test can check, for example, whether a particle has passed a certain age, how fast it’s moving, or whether it has collided with a deflector. Particles that pass the test move on to the next event, while those that don’t meet the test criteria remain in the current event, possibly to undergo other tests. The simple example pictured above details a pFlow dialogue determining the birth of particles linked to a target geometry. The particles can subsequently be baked (using pFlow Baker) into an animation timeline for simple output via .fbx, allowing import into external systems such as Unity or Lumion.

The clip above illustrates the pFlow system imported into Lumion with the addition of a scene created in CityEngine.

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The Making of the CASA Oculus Rift Urban Roller Coaster

Andy — Tue, 26 Aug 2014 14:48:54 +0000

Earlier this year CASA was invited to create a virtual reality exhibit for the Walking on Water exhibition, partnered with Grand Designs Live at London’s ExCeL. While CASA has a tendency to spend a lot of time thinking seriously about cities and data it was quickly decided that a fun and novel way to engage the 100,000 or so expected visitors would be an urban roller coaster ride using the Oculus Rift Virtual Reality headset. Oliver Dawkins, a student on our MRes in Advanced Spatial Analysis is a leading light in urban visualisation and the Oculus Rift, as such he kindly offered to lead the development. In the following guest post, Oliver (of http://virtualarchitectures.wordpress.com/) talks us through the development process….

CASA Urban Roller Coaster from Virtual Architectures on Vimeo.The first tool chosen for this project was the Unity game engine because it provides a very simple means of integrating the Oculus Rift virtual reality headset into a real-time 3D experience. Initial tests were made in Unity with a pre-made roller coaster model downloaded from the Unity Asset Store. However, rather than simply place that roller coaster in an urban setting I wanted to create a track that would be unique to this experience and feel like it might have been part of the urban infrastructure. Due to time constraints it was not possible to model the urban scene from scratch. Instead I decided to generate it procedurally in Autodesk 3ds MAX using a great free script called ghostTown Lite.

Although I like to use SketchUp for 3D modelling wherever possible 3ds MAX was much better suited to this project as it allowed me to quickly generate the city scene, model the roller coaster track, and animate the path of the ride, all in the one software package. After generating the urban scene I used the car from the Asset Store roller coaster as a guide for modelling my track in the correct proportions.

The path of the ride through the city was modeled using Bezier splines, first in the Top view to get the rough layout and then in the Front and Left views to ensure the path would clear the buildings in my scene. The experience needed to be comfortable to users who may not have experienced virtual reality before so it was agreed to exclude loop-the-loops on this occasion. It was also important to avoid bends that would be too sharp for roller coaster to realistically follow. Once I was happy with the path I welded all the vertices in my splines so that the path could be used to animate the movement of the roller coaster car along the track later.

Next sections of track were added to the path I’d created using the 3ds MAX PathDeform (WSM) modifier. As the name suggests this modifier deforms selected geometry to follow a chosen path. Using this modifier massively simplified the process by allowing my pre-made sections of track to be offset along the length of the path and then stretched, rotated and twisted to fit together as seamlessly as possible. This was the most intricate and time consuming part of the project.

In order to minimise the the potential for motion sickness with the Oculus Rift I was careful to keep the rotation of the track as close to the horizontal plane as possible. Supporting struts were then arrayed along the path of the track and positioned in order to anchor it to the rest of the scene. When I was satisfied a ‘Snapshot’ was made of the geometry in 3ds MAX to create a single mesh ready for export to Unity. At this point the path deformed sections of track could be deleted as Unity does not recognise the modifier.

To create the movement of the roller coaster car along the track a 3ds MAX dummy helper was constrained to the path I’d created earlier. This generated starting and ending key frames on the animation timeline. The roller coaster car model was then placed on the track and linked to the dummy helper. It is possible in 3ds Max to have the velocity and banking of the dummy calculated automatically, but I found that this did not give a realistic feel. Instead I controlled both by editing the animation key frames using a camera linked to the dummy for reference. This was time intensive but gave a better result. The city scene, roller coaster and animation were exported as a single FBX which is the preferred import format for 3D geometry in Unity.

Having completed the track and animated the car it was time to assemble the final scene in Unity. First I generated a terrain using a great plugin called World Composer. This enables you to import satellite imagery and terrain heights from Bing maps to give your backdrops a high degree of realism.

The urban scene and roller coaster were then imported and a skybox and directional light were added. The scene was completed with various assets from the Unity Asset Store including skyscrapers, roof objects, vehicles, idling characters and a flock of birds.

To prepare the Oculus Rift integration the OVR camera controller asset from Oculus was placed inside and parented to the roller coaster car. In my initial tests with the Asset Store roller coaster I’d found that OVR camera would drift from the forward facing position. This would disorientate the user and contribute to motion sickness. To prevent it with a quick fix I parented a cube to the front of the roller coaster car, turned off rendering of the cube so it would be invisible, and set the camera controller to follow the cube.

In order to ensure the best possible virtual experience it is really important to keep the rendered frames per second as high as possible. As the Oculus Rift renders two cameras simultaneously, one for each eye, you need to aim to render 60 fps in Unity so as to ensure the user can expect to experience a frame rate of 30 fps.
In order to achieve this I took advantage of occlusion culling in Unity Pro which prevents objects being rendered when they are outside the camera’s field of view or obscured by other objects.

I also baked the shadows for all static objects in the scene to save them as textures which saves the processor calculating them dynamically. The only objects casting dynamic shadows are the roller coaster car and animated characters.
Finally two simple java scripts were added. The first would start the roller coaster and play a roller coaster sound file upon pressing the ‘S’ key. The second closed the roller coaster application upon pressing the ‘Esc’ key.
The reception of the CASA Urban Roller Coaster ride at Grand Designs Live was fantastic and I’m really pleased to have participated. It was a great project to work on and an excellent opportunity to learn new techniques in 3ds MAX and Unity. Having my first VR roller coaster under my belt I’m looking forward to building another truly terrifying one when I get the time, hopefully for the Oculus Rift DK2 which has just arrived at CASA.
On a last note I’d like to thank Tom Hoffman of Lake Earie Digital whose excellent YouTube tutorials on creating roller coasters in 3ds MAX provided a great guide through the most difficult part of this challenging project.
You can follow Oliver’s latest work at http://virtualarchitectures.wordpress.com/…..

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UCL Live Campus Augmented Reality App – Created by Masters Students at CASA

Andy — Thu, 20 Jun 2013 08:23:03 +0000

UCLive is an Augmented Reality Map of UCL developed by students on the Masters in Advanced Spatial Analysis and Visualisation at CASA. Featuring live data, the augmented reality android app works by simply pointing your mobile device at any of the UCL maps across campus.
Running in Unity and mixing a number of GIS and Agent Based Modelling elements, the development is outlined below:

A three dimensional base model was created with SketchUp on top of the UCL campus map;
Moving agents and transports are added into the application to show local bus and tube routes;
Sounds are embedded into the application from the UCL Soundcloud;
Online data on buildings, Twitter and PC Cluster availability – live;
The user’s location is shown in the application map.

Augmented Reality UCL Map

Produced by Ayana Kito ( http://3rdplat.blogspot.co.uk ), Balamurgan Soundararaj ( http://geoidin.wordpress.com ), Daniel Lam ( http://spatiametrics.wordpress.com ) and Nicola Clark (http://cityofblindinglights.org ) it represents the output of the final visualisation project on the masters course. The movie illustrates the app in action:
Take a look at the main UCLive page for full details and updates, we are currently exploring next steps to move the app towards release on Android and iOS.
You can still apply for 2013/14 entry to the MRes in Advanced Spatial Analysis and Visualisation the final full time deadline for applications: August 2nd.

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15,000 Agents: A* Pathfinding

Andy — Tue, 14 May 2013 08:54:11 +0000

Games engines such as Unity are the perfect platform for agent based modelling, they allow a combination of 3D urban cityscapes and navmeshes/grid graphs/point graphs and local avoidance systems. The A* Pathfinding project features an array of techniques for rapid pathfinding or AI development using a low memory footprint.

Agents in Unity

We have only started exploring the possibilites but the results are intriguing, below features a clip of 15,000 agents using local avoidance, the number could be considerably increased using multiple machines:

A* Pathfinding is available in free and pro versions, it is well worth checking out, we have just upgraded to the pro….

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Unity Traffic System – City Traffic

Andy — Mon, 13 May 2013 12:05:01 +0000

Creating a sandbox style traffic system in Unity is a challenge. As our previous posts have shown agents can use NavMesh and calculate shortest paths but the hit is high on processing which in turn limits the number of agents in a scene. Sander van der Vegte is a multidisciplinary game developer who for the past 12 years has fortunate enough to make a living creating games, part of his current development process is a city traffic game and thus finding ways for natural behaviour while maintaining a low processing requirment.

Unity City Traffic

The clip below is a recording of an autonomous traffic system. Cars drive around while aware of crossings and other vehicles. When something is blocking their path, they will stop. If it takes too long, they will back up and look for another path, the basic ruleset allows for humorous situations:

Traffic system from Sander van der Vegte on Vimeo.

Within the development the user is able to click on a car to take it over while falling off the edge triggers the random camera again.
It is well worth heading over to http://sandervandervegte.nl/ to view his other projects and to keep up to date on City Traffic.

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Police Agent City Ball – Unity/NavMesh and CityEngine

Andy — Wed, 01 May 2013 12:54:17 +0000

The natural conclusion of our recent posts on Unity and CityEngine is of course a physics/navmesh police chase with the agent target being a drag and drop ball.

Police Car Agents in the City

We will release a version next week on the win/mac platforms for those interested – the aim was to explore shortest path modelling of agents in Unity within an urban scene:
The concept was developed as part of our Masters course here in CASA, to explore the development of 3D interactive urban scenes…

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Augmented Reality City Table Top – Unity, CityEngine and Vufoira

Andy — Wed, 24 Apr 2013 15:00:24 +0000

The Vuforia AR Extension for Unity allows developers to build AR apps using the cross-platform game engine – Unity. Working with both the free and pro versions of Unity, Vuforia is not only free it is also one of the best out there in terms of tracking and image based tagging.

Table Top AR City

Running on either iOS/Android or direct via a webcam it allows the integration of other Unity assets into scenes. As such you can create a table top digital city complete with agents all linked to an image based marker and running as a native iOS app:

We will be exploring this further over coming weeks, it opens up a lot of possibilities for augmenting city models (and office desks) with urban data visualisations via custom made iOS/Android apps….

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Shortest Path Modelling and NavMesh in Unity and CityEngine

Andy — Thu, 18 Apr 2013 12:13:49 +0000

Shortest path network analysis, pedestrian modelling and moving agents around complex city scenes has always been a specialised domain. As regular readers will know we have always taken the view that game engines are arguably better suited to agent based modelling – especially in terms of pedestrian and transport than more traditional packages.

Agents in Unity

With a mix of Unity NavMesh and some simple Javascript it is possible to create a city wide navigation mesh. Below is out first example using agents to follow a target (viewable in 1080p):

We will be exploring this further over coming weeks…

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Shortest Path Modelling and NavMesh in Unity and CityEngine

Andy — Thu, 18 Apr 2013 12:13:49 +0000

Agents in Unity

The post Shortest Path Modelling and NavMesh in Unity and CityEngine appeared first on Digital Urban.