Blog for Matt Vitelli at GarageGames.com

TGEA Advanced Shaders (Image Heavy)

Matt Vitelli — 2008-11-10T01:42:20+00:00

I've been working hard on post processes since late June. Only recently have I implemented many of the effects TGEA users have desired for years. This has taken a great many months, but things are finally coming together. I've learned powerful lessons and valuable techniques for working with image-space. Below is a compilation of the past few months.

God-Rays
Similar to my light-extrusion mapping from an earlier plan, only this creates one based on objects in the scene and collision intersections with the sun.

Motion-Blur

This uses the good ol' frame-to-frame blur method. An example of this can be found in RenderMonkey.

Real-Time Atmospheric Day and Night Cycles and Dynamic Atlas Shadows

Video Here
This is useful for realistic day and night cycles. The sun is dynamically generated using a shader and the entire sky uses 3 lookup tables. This is a performance enhancement compared to the many textures used in the original skybox class. It also is visually more appealing.

Dynamic atlas shadows are also part of this. Unfortunately, I have no video of this in action, though it can be clearly seen in the screenshots. The shadowing uses a height-tracing algorithm similar to relief mapping. This has some benefits to standard shadow mapping, but also some disadvantages visually. Ambient-occlusion is also calculated in the shader.

Day

Sunset

Night

Atmospheric Glare Using Diffraction
Essentially, this is the effect seen when a viewer squints their eyes at a light source. The halo gets skewed in seemingly random directions when you squint your eyes, creating a cross in glare.

Depth of Field
Pretty good technique, but it requires a high-precision, high-resolution depth map for quality. (R32 texture-type)

Normal-Based Screen Space Ambient Occlusion
This is similar to the traditional depth-based approach, only it is done using the normal-angles to calculate occlusion. It tends to be more accurate and gives better results and less of the "black aura" that's seen in depth-map based approaches.

Without AO

With AO

Shaders Galore! Texture-Space Diffusion, God Rays, and Light Extrusion Mapping!

Matt Vitelli — 2008-07-29T09:36:35+00:00

Being several months overdue for a blog, I decided it was time to write one.

A great deal has happened over the past few months. I've done a lot of work with TGEA and have been working on an assortment of post-processing effects.

I am honored to say I am now an associate of Garage Games and hope to continue doing work to improve Torque technology.

For starters, I have written several iterations of deferred renderers. For those unfamiliar with a deferred renderer, the general idea is to save out
position and normal information from the entire scene into a texture. This allows you to control your lighting process almost entirely on the GPU.

I've written my own algorithm for Screen-Space Ambient Occlusion. In ambient occlusion, light comes in from every direction. My algorithms use the
8 surrounding cardinal directions to test for occlusion and shade based on that. It is run completely as a post-process using scene depth information and
requires only 8 samples, unlike many SSAO algorithms. The picture below is a crude example, using 32-bit precision. Good SSAO (and really, most post-processing effects) should use 128-bit textures. This does, however, have many performance drawbacks making a subtle effect such as SSAO somewhat pointless.

I've also been working on texture-based diffusion. While the terminology may confused some, it is really quite simple. You perform your diffusion and lighting in one pass, saving the result into a texture. You then perform many gaussian blur filters and adjust color operations to suit your needs. Then, the result is reapplied to the mesh and specular is calculated. The results produce soft, realistic skin. So far, the major problem with incorperating this into TGEA has been storing every diffusal texture, seeing as every mesh requires a new one.

SSAO and texture-based diffusion are great, but the real focus of this blog is to expose a new rendering technique I'm coining as "light extrusion mapping". Light is "extruded" from pixels on a texture map and the result is rendered as a post-process. This means NO geometry is being rendered for each ray. Many games are adopting similar effects, including Crysis and STALKER.
Plenty of neat effects can be done, some of which include god rays, foliage sun-scattering, and truely emissive images. Below are some of the results that can be accomplished with such light extrusion maps.

The really neat thing about this is that a light extrusion map is just a simple alpha channel, but it can easily be scaled to allow ranges of color from every channel.

Day and Night System

Matt Vitelli — 2008-05-15T01:17:42+00:00

For the past few months, I've been actively pursuing terrain and skybox code to allow dynamic day and night cycles. Day and night cycles are important, especially in sandbox games. Currently, I've been getting some impressive results that are fairly inexpensive. Currently the code requires the use of a specific art pipeline. In time I plan on making the system completely automatic so developers are able to drop levels in and automatically generate the necessary media for the level. In the future, I also plan on having a per-surface detail mapping system allowing users to add as much detail as necessary to the scene. It would also be spiffy to implement a layers system similar to Id's tech 5.

Adam Beer has been extremely helpful in his testing, feedback, ideas, and thoughts. Below is a video he created using the new terrain and sky updates:

www.box.net/shared/xa4pvflcsc

Here is a YouTube video demonstrating the skybox system.

Here is a YouTube video demonstrating the terrain shadowing updates.

Illumina Screenshots!

Matt Vitelli — 2007-09-27T06:19:00+00:00

Hello everyone, it's a great time to be an indie. With IGC just around the corner, we're trying to get a small demo ready. Even if a playable demo isn't ready, a graphical one will be provided at the very least. :) At any rate, I've learned a lot in the time I've worked with on Illumina. It's an exciting project that's constantly looking for new talented individuals.

In a few days time, I will write another plan about the process that went into bringing these models from the prerendered images to in-game shaders. The process that went into this is exciting. Without further a-do, I present to you Illumina. These screenshots seriously don't give it justice..

Remember, you'll be able to check out these in depth at IGC.

Matt Vitelli

Forgotten Lands, Real-Time Ambient Occlusion, and Motion Blur!

Matt Vitelli — 2007-08-14T04:05:50+00:00

Have I helped you? Feel free to nominate me for an associates membership. :)

Progress is going steady on Illumina and there are some really amazing things in development that I'm really proud of.
Illumina is perhaps the best looking game running on TGEA as of current. But more info will be released on that in the coming weeks.

Visual Features

Dynamic Ambient Occlusion
Ambient Occlusion is one of the big features in the works. This technique is available to anyone using a shader model 2.0 card. With a new algorithm developed by yours truely, ambient maps can be calculated on the fly without any noticeable performance loss.

Radial Motion Blur
Also used in Illumina, this technique works well for cinematic elements.

Relief Mapping on Shader Model 2.0
This was mostly an experiment to see if it could be done, and indeed it can. You lose quite a bit of smoothness because you have to reduce the amount of samplers being applied. I posted the source code here.

I believe that sums up this week's plan. Feel free to drop me a line if you have any questions or comments.

Illumina, Forgotten Lands, and Shaders!(Screenshot heavy)

Matt Vitelli — 2007-08-03T06:12:09+00:00

Hello everyone, it's been a while since I wrote up a plan, so I figured it was time for another write-up.

What's happened in the last few months?

I've continued shader work more readily and now feel extremely comfortable with HLSL.

Progress on Illumina:

I've been working on Illumina for a bit now and now I'm happy to say I'm doing visual effects for the game.
Here's a few screenshots of the new lava level. Including a few with motion blur!

After working on my RPG for several months I ultimately came to the conclusion that it was impractical for a 1-man team with absolutely no budget. I went back to my older designs, including a game called Forgotten Lands. I can't talk much about the actual game, but I can say that it will be visually advanced featuring the most recent effects. It will have complete shader model 2.0 and 3.0 support.

What's in Now:

Skin Shading:

Normal Mapped Terrains:

Parallax Occlusion Mapping on Shader Model 2.0:

Atmospheric Scattering Shader:

Various Tools and Projects (Screenshot Heavy)

Matt Vitelli — 2006-11-08T01:34:44+00:00

I figured it was time for another blog post. Basically I'm creating a first person RPG of sorts using TSE (and possibly something using TorqueX if I'm added to the next beta). I'm still thinking of ideas on how to organize a persistent world. If anyone would like some of the code for this just email me and we'll work something out.

Currently what I have gameplay wise includes:

Wanted System - If you slaughter a NPC then his friends or the local guards will come after you

Basic Melee - I chose the "Dark Messiah" style combat of holding your mouse down and releasing to attack.

Saving/Loading System - This saves your position, health, stats, weapons, the mission you're on, and various other details

Cinematic Mode - A special in game cutscene setup to give a cinematic feel. Along with this you can edit text on the fly so things like subtitles can be done with ease.

RPG Stats - These include level ups, strength, speed, defense, etc.

Fame/Infamy - Have you chosen a life of good or horrible evil? This affects how every NPC in the game reacts to you.

Falling - Say you miss a jump or are pushed off the edge of a building. You are given 1 second to grab onto the ledge and pull yourself back up.

Along with this I've done/ am working on various rendering techniques, both onscreen and off. Some of which include:

Cloud Rendering - This is split up into a few categories. Basically I have the skybox cloud system to act as persistent clouds, but along with this I have a series of planes, each mapped with their own different material thus giving the developer a fair amount of control. In the future I may add a billboarded system with particle effects. Hopefully I'll come up with something similar to Air Ace's clouds.

BSP Terrain - This is by no means what I'll be using for a final terrain system, but I thought it was a neat experiment. What you're seeing here was created in Constructor and contains over 7800 brushes! As you can see it is very tile-y but was a neat experiment nonetheless. Constructor is by far the best BSP tool I've used.

Water Rendering - I've added relief-mapped water to TSE. For those who are not familiar with relief mapping, it uses a linear search for depth. This proved to be surprisingly inexpensive, but ultimately I'll replace this with actual vertex waves further down the road.

Video

Day and Night System - See for yourself!

To aid members of my team that are unfamiliar with Torque Script I am making a series of tools to help ease the process.

NPC Creator: As it currently stands, the NPC editor creates a new PlayerData datablock and allows the user to modify all of the "important" parameters. I may release this in time, but overall it's fairly basic. In the future I will tune it to allow a facial editor similar to The Sims or Oblivion.

Quest Editor: This is a tool I hope to create in time. Basically it gives a few generic quest starting functions, what happens in the quest, and what is required to finish the quest.

Future Ideas: I'd really like to purchase FaceGen without being too much like Oblivion. It seems like an obvious choice, as I don't have the budget to contract artists and have them create hundreds of heads. The below is a free mesh on their site and I would like to state that I have not bought this product yet.

Along with this I am working on a TGB project. It incorporates PGC, or procedurally generated content. In this case NPCs, the world, and quests are all generated randomly using logic puzzles. I'm afraid I can't talk much about it but I am working with Brian Ross. The goal is to basically be able to generate an endless Zelda-like game with the click of a button.

With the PGC content I hope to apply this to FaceGen (when and if I integrate something like it in Torque) Think how great it would be to start a game and have all of the characters looking new. I really think PGC could be the future for some games. It allows virtually endless possibilities.

Once again, if anyone wants to see any of my code, shaders, or just wants to chat feel free to contact me.

Thank you,

Matt Vitelli

The Past Year

Matt Vitelli — 2006-09-16T07:09:00+00:00

Well, my last plan was posted back in October roughly a week after I got back from Indie Games Con 2005. I figure it's time to write another about my current endeavors. After IGC and the TSE tech demos I really wanted to learn how to use TSE. I spent the first few months just learning how to use it along with general Torque things. I started generating Atlas terrains, using relief mapping, learning the material system, etc. Shortly after I started work on a small FPS with a friend. We aimed a bit too high and ended up failing. I definitely wasn't ready for a game like that.

By then it was Christmas. I took Jeff Tunnell's advice and bought a new computer with fancy video cards. A must if I wanted to try shader model 3 development. After spending the next 2 months trying to incorporate slightly more difficult resources, Atlas terrains, and Difs into my game I soon learned that this was too much for 1 person.

I took a small break from TSE to try out some of the new shader addons people were doing with the CG language. It was fun to experiment but just didn't feel the same as TSE. Soon it was June and Milestone 3.5 was out. I was so excited when I learned Atlas 2 was in there along with batch rendering. I started work on another unfinished project called Forgotten Lands. (If anyone remembers I made a few forum posts about it. It was basically a dinosaur hunting game.) I was able to make a short and simple demo though I couldn't release it as it violates Daz's EULA. I started work with full screen shaders. After a lot of help from Ray Gebhardt and Josh Moore I was able to do some neat things.

By August I was beginning to code my own simple shaders. I took some programming classes that greatly increased my skills. With IGC only a few months ahead Ben Ewing, Brian Ross, and I started work on a small scale RPG for it. Within the first 2 weeks we had the core gameplay in. We had dialogue, guards, civilians, gold, weapons, a law system, you name it. Only a few weeks after we learned that IGC had been cancelled. That was a huge let down but progress still continued.

Now in the last few weeks Torque Shader Engine Milestone 4 has been released. This has been a huge excitement for me as I was able to do so much with the bloom and DRL values. It's very exciting to see what everyone is doing at Garage Games. And of course, no plan is complete without screenshots. Please mind the place holder art. :)

-Matt Vitelli