Still alive

It have been 3 years since my last post!
I have been wanting to post here on a regular basis, but it always end up in me wanting to re-code the website or something else gets me to postpone it. Thus, I never get to write anything.

I have been quite busy though. I started at the Danish University of Technology in 2010 and are studying Mathematics & Technology. I am now on my 6th semester and just started writing my bachelors thesis about Procedural Content Generation.
When I’m done with my bachelor I will continue with a master, probably in Mathematical Modelling and Computing. So I still have a few years of studies ahead of me.

Anyways, I hope that I’ll be able to post more often in the future. I have some interesting projects I’ve done that I would like to share.

Until next time, take care.

Ronzan - 05 marts 2013 14:19 0 Comments
Tags: Misc

Started updating

I thought it was about time to put up some updates. I have quite a few projects going on, but I haven't really gotten around to take a few screenshots.
So here are some screenshots from my terrain engine test project. The terrain is generated from a heightmap. So far I've implemented terrain patching with LOD, quadtree, multitexture splatting and terrain self shadowing. See screenshots here

Ronzan - 21 februar 2010 23:45 4 Comments
Tags: XNA

Multiple Lighs and Shadows

I just posted a "question" at the xna forums, and thought I'd might as well post here too just in case someone drops by and wants to share their thoughts ;)

The post on the forum is here

After getting my pointlight cubemap shadow mapping to work I am facing a new challenge.
I have read papers, studied samples and made prototypes. But I just can't decide/figure out what the "best"(tm) approach to this ordeal is.

Possible methods of dealing with multiple lights and their shadows I have found so far:

1. Multiple shadow maps - One depth pass per light, resolved to a unique texture.
a) Light contribution in a single pass (looping over lights).
b) Light contribution in multiple passes (additive blending).

There are several flaws to this approach:
Needs many textures, possibly exceeding the shader maximum.
Limited number of lights in a single pass, too many additive passes and gets too slow.

2. Single shadow map reused - Multiple passes (if possible at all?)
a) One depth pass and one light contribution pass per light (additive blending).

Flaws here could be poor performance of many additive passes.
I never succeeded in implementing this, I had problems rendering the shadow maps in between the light
passes, which I guess makes sense (as there is already stuff in the GPU buffers etc).

3. "Standard" deferred rendering.
a) Pre-Z pass, G-buffer pass, one shadow/light pass per light.

This looks like an optimal render method for dealing with multiple lights and shadows
not to mention other benefits like post-processing.

The main thing that bugs me (and everyone else it seems) about this approach is
of course the alpha/transparency issues. Especially in scenes with lots of foliage and particle effects.

I think my main issue with all of this is shadow mapping.
For lights alone I could live with a "multi-pass multi-lights" approach. But when adding shadows to the equation
it is just slow / complicated / smelly and what not.

Then I ran across this article here:
It's Matt's (MJP) article about Deferred Shadow Mapping, I still need to re-read it a few times to fully understand it I think,
but it looks like an excellent approach.
Anyone have experience with this method? Is it a suitable approach?
Can I render multiple shadow passes into the same shadow texture(?).
I'm about to test it out but any insight is appreciated.

Now, do I actually have a question hidden in this wall of text?
I'm not sure, however I find it helpful to write things down when puzzled.
I'm pretty sure that not everything I've written above is 100% accurate, so feel free to enlighten me (no pun intended).

I have already searched the forum and googled a fair bit, but there are so many terms involved and I have probably missed something.
A few of the more interesting posts, papers and articles I've read so far: forum posts - this, and this, and this
Other resources - Deferred Shading presentation by Shawn Hargreaves, Deferred Shading tutorial

I would appreciate any thoughts on the subject, how do you handle this, do you just use a single shadow caster, do you live
with the shortcomings of deferred rendering, do you avoid pointlight shadows etc.

Ronzan - 27 januar 2010 21:56 0 Comments
Tags: XNA, Game