Michael Quandt's Blog - Latest Comments

Re: About

Sam Stokes — Tue, 13 Mar 2012 17:18:24 -0000

Michael, great work on ScriptTD, I have some students who used it for the Imagine Cup and have a video on it (hopefully they haven't marked it private) here:
http://youtu.be/D7o1ceAFGjk

Re: ScriptTD

Tmac — Tue, 15 Nov 2011 20:35:31 -0000

Thanks for making this, it's very helpfull.

Re: XNA Cross-Platform Editing in Real-time

Lucas Moffitt — Sun, 10 Apr 2011 01:42:21 -0000

Re: XNA Cross-Platform Editing in Real-time

Chr0n1x — Sun, 10 Apr 2011 01:19:50 -0000

When I write a game that uses it and post screenshots. That's where they will be.

Re: XNA Cross-Platform Editing in Real-time

Lucas Moffitt — Sun, 10 Apr 2011 01:18:16 -0000

Where's the screenshots at?

Re: Action Based Input Manager w/Events in XNA

Esente — Mon, 17 Jan 2011 23:52:10 -0000

Really nice. Would you mind putting up a small example of how to use your Input Manager?

Re: Light Pre-Pass Round 2

Chr0n1x — Fri, 04 Jun 2010 19:37:44 -0000

Matt Pettino covered Inferred Rendering earlier this year in a blog post http://mynameismjp.wordpress.c...

I have not tried the technique, and don't really have any plans to at the moment, however the technique looks interesting from the paper.
I noticed Little Big Planet used a similar method to gain transparency, although without the DSF, it seems they use stippling, but take advantage of the way the PS3 handles 2xAA to get an extra layer.

It certainly has a practical solution to the transparency issue, and if you are interested in gaining full flexibility at the cost of some overall image quality, it is certainly a viable solution given the right hardware. This seems to be a case of using the most appropriate technique for the target hardware, and of course it also needs to be based on the requirements of your game.

Re: Light Pre-Pass Round 2

Chr0n1x — Tue, 01 Jun 2010 07:42:27 -0000

Matt Pettino has a good article on Inferred Rendering, although he does not really compare the different techniques on offer in much detail.
http://mynameismjp.wordpress.c...

At the moment I do not really have any time to look into other rendering techniques, I'm trying to get a good shadowing system done, and some other core utilities for my engine. At the same time I'm dreading the migration to XNA 4.0 HiDef.

I read the paper for IR when it came out, and after reading through Matt's article on the topic, I would have to say that just like LPP, it seems to be a case of the best technique for either your game, or target hardware.

Having transparency built into the technique is quite nice, assuming you are willing to take the image quality hit that you get from a 1/4 light buffer. You could try using buffers 4x your back buffer size, but with modern resolutions this leaves you with giant surfaces, and on the XBOX that will lead to a lot of EDRAM tiling.

It may be something to look at in future, assuming nothing newer/better comes out. When it comes to transparency, at the moment I am more interested in Order Independent Transparency, although that needs more than what XNA provides at the moment.

Michael

Re: Light Pre-Pass Round 2

Quang Anh — Mon, 31 May 2010 11:08:30 -0000

What about Inferred Rendering? I remember not seeing it anywhere in your blog. But it might not be a good choice comparing to Light Pre-pass or even vanila Deferred rendering

Re: [LPP] Ambient Lights

Alejandro — Thu, 15 Apr 2010 02:48:04 -0000

Tips annotated!
Reusable flexible code is half the battle.

I can't wait to get my hands on XNA 4.0 also to start messing around with the render states objects and new render target rules so I can set aside current rules. The more work is done in 3.1 the more to change with 4.0. Hopefully test something on the phone.
I'm really glad by the direction XNA is taking, who knows what we will see in the future.

Re: [LPP] Ambient Lights

Chr0n1x — Thu, 15 Apr 2010 02:34:26 -0000

Hi, thanks for your input.

Yes you certainly can clear the device to do an ambient light, and if you are fine with restricting yourself to one ambient light or coding that directly into the renderer, then it is perfect.

I decided for the tutorial to show the longer, but flexible method, however both work quite well, and generally you only need one ambient light anyway. (I am aiming to be very generic/open with my engine, so who knows what lighting setup I want to use in future :))

Yes you are right, the compiler should certainly remove unused methods, and hopefully unused variables. I add the pre-processor directives so that I can play around in future adding/disabling techniques. It also helps me in slightly more complicated shaders - by removing a #define I can trigger compiler errors telling me where the references to the now missing method/variable are, without having to delete the actual method, which I may want to reuse later.

All of the code presented comes from my private engine at a certain point in time. I use that engine to experiment with techniques, and just copy over and edit the required parts for a sample.

I'm glad you like my blog. =D
I hope to have some more content coming soon, just finished up a big push towards a product release at work, and I have not had the time to do anything in XNA. I am also debating whether to wait for XNA 4.0 (HiDef) or continue in 3.1 and figure out some migration path when I can build against 4.0.

Re: [LPP] Ambient Lights

Alejandro — Thu, 15 Apr 2010 02:08:42 -0000

Hi there Michael!,
I have been playing around with rendering techniques, although still way behind in the process...

I would like to comment about ambient color though, with a tip that John David said in his blog http://my-pseudocode-life.blog...

Basically is to flash the device to the ambient color -> device.Clear(ambientColor), it's almost free. It would only work when additive blending all lights in the lighting pass of LPP. When the lighting pass actually starts blending all the lights, the ambient color is already there. You can clear it to a color with alpha zero so it doesn't mess with the speculars (in case specular is in alpha as your sample).

And a question:
Roughly seeing the sample I noticed that in your common.fxh, you have separated some sections using #ifdef preprocessors, so the actual .fx file only will get what is has been defined its "#define" directives. The question is, is this just a "best practices" to keep order in the shaders? or is it somehow faster since the shader has less "methods" to access to?
(Although to my understanding until now, the shader parses the compiled file at run-time, where the unused fields and methods will be discarded on the compiled file, but you never now)

Nice blog by the way!

Re: [LPP] Ambient Lights

Pete — Sat, 03 Apr 2010 16:19:23 -0000

Nice!

Let's hope we can share depth buffers among different rendertarget "buckets".

https://connect.microsoft.com/...

Re: Light Pre-Pass Round 2

Chr0n1x — Fri, 12 Mar 2010 18:20:42 -0000

That will come in future. I plan to do articles on other light types like Point/Spot lights, and the first of those will have information on how to reconstruct position using arbitrary geometry.

I will have further information on reconstructing position when using a fullscreen quad (like in the sample) next week.

Re: Light Pre-Pass Round 2

Barry — Fri, 12 Mar 2010 09:58:34 -0000

Perhaps some more information on reconstructing the linear depth for other volumes?

Re: Light Pre-Pass Round 2

FiSH — Fri, 12 Mar 2010 01:08:47 -0000

At last! :)

Re: An update on LPP + Sample

wp — Thu, 04 Mar 2010 02:36:39 -0000

hi，i need the help， can you send your shader files to me?

Re: Rewrite of LPP Article Planned

Chr0n1x — Tue, 09 Feb 2010 00:24:32 -0000

I am writing it at the moment. Some issues during the new year, and the start of my internship delayed it unfortunately.

This time around I am aiming to get a sample out with the article, and the article will have more imagery/diagrams to help describe things - this unfortunately is delaying me, as I have to split the sample from my current engine source code.

Thanks for your patience, it should not be much longer.

Michael

Re: Rewrite of LPP Article Planned

Jizz — Mon, 08 Feb 2010 23:30:04 -0000

Any news on when this new article will be up?

Re: Important Additions & Fixes to LPP Implementation

Charles Humphrey — Fri, 04 Dec 2009 17:47:22 -0000

I hate render states too :D

Nice work and well done tracking those issues down :)

Re: Important Additions & Fixes to LPP Implementation

Pete — Fri, 04 Dec 2009 12:12:47 -0000

Thanks Michael for the clarification and keep up this great job!

Re: Light Pre Pass in XNA: Basic Implementation

Michael — Wed, 02 Dec 2009 01:12:20 -0000

zizi :
Hi, nice post. Are you doing something bigger using this technique, or is this just an educational sample? Also what kind of shadowing are you going to implement? Looking forward to your next post on this.

Thanks :)
This is currently the core of my own engine's renderer, however from this point onwards I have split the codebase so that I can show off different ways of doing things.

This is just the first of multiple samples/articles that will build upon this, and as I add features to my engine, if they relate to this I will probably write about them.

As for shadowing, I am not sure at this time, I may do an article on adding basic shadowing to this system, or just go straight into whatever technique I will use myself.

Re: Light Pre Pass in XNA: Basic Implementation

zizi — Wed, 02 Dec 2009 00:32:35 -0000

Hi, nice post. Are you doing something bigger using this technique, or is this just an educational sample? Also what kind of shadowing are you going to implement? Looking forward to your next post on this.

Re: Light Pre Pass in XNA: Basic Implementation

Michael — Tue, 01 Dec 2009 19:37:24 -0000

Pete :
Nice article!

Maybe you don’t need to implement a forward renderer for transparent objects. Read this article:

http://diaryofagraphicsprogrammer.blogspot.com/2009/11/order-independent-transparency.html

(in particular “Reverse Depth Peeling”).

Yeah that is true, there are alternatives that do not require a separate renderer for transparent objects. Another technique is using stippling to "alternate" between layers.
(See Inferred Lighting, SIGGRAPH 2009)

http://graphics.cs.uiuc.edu/~k...

That is something I plan to look into for my own engine, and certainly write about if everything works out.

Re: Light Pre Pass in XNA: Basic Implementation

Charles Humphrey — Tue, 01 Dec 2009 10:17:34 -0000

Yes, great post, going to have fun playing with this now :)