DeleD Community Edition

[Paul-Jan]

Hi guys, the post below is something I just posted over at http://www.pelicancrossing.com/forum/index.php , thought it might be useful to post it here as well



Some remarks that might or might not help out:

1. I think we badly need to build some feedback and warnings into DeleD about total lightmap size when generating a lightmap. Quite some users have been attempting to light a couple thousand of polygons with both minimum and maximum texture size set to 256x256 (or even higher). A quick calculation tells you that is 256x256*3 bytes per polygon. That's easily a few hundred mb of lightmapping information for a scene. Downright kills both performance and download times.

Of course, we didn't expect people to actually do these kind of calculations in their head when modeling. However, we did expect people to pick up hints like their computer spending hours and hours calculating the lightmap, running out of memory, the multiple gig upload to their webspace, stuff like that

2. Lightmaps should never be converted to a lossy fileformat like JPG. The boundaries between individual textures (packed in for example 512x512 lightmaps) will be corrupted, resulting in bad artifacts. This is the reason why the lightmaps are stored as .bmp's in the first place. PNG compression (lossless) will do fine. DDS might do even better, as it can be stored compressed in texture memory as well. Both formats are on our todolist, but currently Not Yet Implemented. Once we do, DeleD will ask the user for the preferred format to store the lightmaps in. Until then, you'll have to do the conversion manually.

3. To make sure there is no confusion about this: setting the LightMap Size to 512x515 does _not_ restrict total lightmap size to 512x512, it just means the packed bmp's produced will each be 512x512 size. There is no way to directly restrict total lightmap size in DeleD, we decided to take an approach where quality is leading, not size. I understand how, especially for web deployment, more feedback on total size is necessary... please refer to remark (1)

4. Min and Max Individual Texture Size are a Good Thing (tm). The average scene consists of a lot more small than large polygons, so setting the minimum value a little bit lower results in a lot smaller texture size at virtually no cost (as it only affects the smallest of textures in your scene). I personally usually start out with 8x8 Min size and 128x128 Max size, using 2 blur passes. That is, after I am mostly done placing lights, because during that phase I set everything to 8x8 and turn of blurring and shadowcasting.

5. DeleD Lite lighting is restricted to a fixed 32x32 Min/Max individual texture size. Not only does this result in pretty bad quality lighting (without crease angle or filter support), it also quickly leads to huge lightmaps. A quick calculation learns that only 256 textures fit into a single 512x512 lightmap. In other words, Lite lighting is not suitable for lighting anything serious, especially for Web Deployment where the size issue is a lot more severe. Note how we kinda did this on purpose

6. We might consider changing the Lite restrictions a bit in the future. We also might consider offering the user a different lightmapping scheme, where size is leading (i.e. the user sets the desired Total Lightmap Size, and the renderer just uses a constant lumel density on all surfaces). As always, any ideas you guys have on these and other issues are more than welcome!

[condrula]

ooopss (sorry I read better this time...)

[Paul-Jan]

I have no idea what you said oops for, but I am sure you are forgiven *lol*

[Brian]

All I can say Paul, is that this area needs to be addressed. Kind regards Brian.

[trucker2000]

That makes since. My question is...why in the world does deled make so many lightmaps anyway?
_________________
Some day I will grow up and be a real modeler.
"Never give up! Never surrender!!"
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Invidia gtx560 video card
Windows 8 (worst op sys Ever)

[Paul-Jan]

Hi Trucker2000,

What do you mean by "many lightmaps"?

Strictly sticking to commonly used terminology, DeleD creates:

a) 1 lightmap, consisting of

b) 1 or multiple lightmap files, depending on your settings. The higher resolution you want, the more files you get. The more polygons you use, the more files you get. Then again, the more pixels per file you allow for (be ware of old gfx cards not supporting huge textures), the less files you need. Each lightmap file consists of

c) multiple individual lightmap textures, one per triangle.

I assume you are refering to b). Try lowering your lightmap resolution, especially the minimum individual texture size.

[trucker2000]

Ok, will give that a try. (was planning on it anyway.)
_________________
Some day I will grow up and be a real modeler.
"Never give up! Never surrender!!"
Sys specs:
asus
8 gigs ram
Invidia gtx560 video card
Windows 8 (worst op sys Ever)