Quote:Original post by sandy
I was looking forward to a good article, but sadly disappointed. IMHO the Bloom article is excellent. In fact I implemented the technique beautifully into our engine from Bloom's article. This new article does not really add to, or simplify Bloom's original article in any way as it seems to me.
In fact, the sample application is very poor, I thought. All it does is render a single quad using a few different textures and pre-generated alphamaps. This is not "splatting". The idea of splatting is that the alphamaps are created on the fly (at run-time) based on a textures influnce at any point on the terrain. Any monkey can create some alphamaps in photoshop and render textures on a quad using them.
Glasser even goes on to mention a flaw in the system (i.e. seems) that he has not found an elegant solution for. This makes me wonder if he has even read Bloom's article? Bloom solves this problem quite well by creating alphamaps not just based on the current chunk, but also the eight surrounding chunks. This ensure that the alphamaps matches at the edges, eliminating the seems.
If anyone is serious about implementing texture splatting, just stick with Bloom's article. You can't go wrong. |
You can generate the alphamaps on the fly, but there is also no reason you can't precompute them. I find the second option more flexible, so that's why I chose to use it. The core of splatting is with the blending. I really wanted to keep the demo simple. While I could have done something more elaborate, it would have only been bloat in the code. In hindsight I probably shouldn't have called the technique the true texture splatting, but the end effect is very similar.
About the seams... There is a solution to it. You can use a 34x34 texture and have the borders be shared, or you can stick with 32x32 and have a 30x30 usable area. Again, I didn't want to make things too complicated, and the solution is less than ideal. I've gone through Bloom's method, and while the seams aren't as apparent, they are still there for the same reason. It doesn't end up being a huge problem once you get ground cover in things on. As a bit of a comparison, I noticed WoW doesn't even deal with them.
Sorry you didn't find it helpful.
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