Radiosity

dlangdev · Post by **dlangdev** » Thu Jan 03, 2008 3:07 am

just wondering if anyone have comments or experience on generating bake maps in blender, then ported over to irrlicht for blending.

i've provided a sample radiosity demo image below. one thing i noticed was the jaggies at the shadow edges.

what i did to lessen them was to subdivide the mesh to hi-poly.

dlangdev · Post by **dlangdev** » Thu Jan 03, 2008 9:36 am

here is another demo showing the textured models without radiosity.

i'll post the one blended with radiosity map later.

dlangdev · Post by **dlangdev** » Thu Jan 03, 2008 9:41 am

btw, i'm giving my demo textures away for free.

http://farm3.static.flickr.com/2103/216 ... 7a46_o.jpg

http://farm3.static.flickr.com/2119/216 ... f859_o.jpg

http://farm3.static.flickr.com/2341/216 ... 04b1_o.jpg

http://farm3.static.flickr.com/2024/216 ... 6f69_o.jpg

http://farm3.static.flickr.com/2330/216 ... 3c1c_o.jpg

vermeer · Post by **vermeer** » Thu Jan 03, 2008 3:55 pm

I don't know how you did it, but jaggies an come with very low res lightmaps. Or applied to very large 3d areas. Also, if you are baking radiosity from blender, the only way I know involves mainly baking light into vertex colors, you would need a crazy subdivide to have same accuracy than with texture methods. (max , etc, have more complete gi, even more if use a integrated renderer like final render or brazil)

In blender there's not yet a very solid GI solution(surely incoming). But you can fake things with Ambient occlussion lighting, maybe using also some coloured lights, maybe the help of some vertex colors and self illumination here and there...

Still, I haven't grabbed a format script for Blender that I know for sure will export the mesh with the second uv channel and its lightmap...I think Gandalf(diego) is working on it for b3d, but not sure.

In the meantime, Giles[3d], if know somebody who purchased it (and unless like me, has time

) , that one does actually radiosity and export it ready to go as b3d exported file , and some other formats...

But I really really hope to see it for blender and b3d format...

omaremad · Post by **omaremad** » Thu Jan 03, 2008 5:00 pm

If the jaggies are at polygon edges then its likely to be the filtering, use a dilate filter several times in gimp on the baked lightmap.

dlangdev · Post by **dlangdev** » Thu Jan 03, 2008 9:24 pm

yeah, that's what holding me up. i'm still looking for that python script that will bake them to texture.

also, i found no problem in the ambient-occlusion map baked-in into the texture when i was testing it several weeks ago.

dlangdev · Post by **dlangdev** » Thu Jan 03, 2008 10:01 pm

well, if i can't move forward because the python code is missing, i'll have to skip it and test it using hlsl code.

i'll just use the diffuse for radiosity which is basically this...

Code: Select all

float diffuse = 0.5 + 0.5 * dot(lightDir, normal);

from there i can control the brightness by changing the numeric values.

dlangdev · Post by **dlangdev** » Thu Jan 03, 2008 10:11 pm

omaremad, that's a good one, i'll remember that.

thanks/shukran

oldskoolPunk · Post by **oldskoolPunk** » Fri Jan 04, 2008 1:31 am

Blender's radiosity solutions, while they eat up the cpu cycles, are pretty incredible. Baking is as simple as clicking the BAKE button with VColLight selected in the material. The renderosity panel also gives you quite a bit of settings as to how much you want your mesh cut up. No need for any subdivision yourself. It will divide the mesh up as much as you want it to, more in areas with lots of contrast and less in areas of more solid colors. And it even retains the save UV unwrapping so the baked texture will perfectly fit your original mesh.

At the moment only Cal3D and Collada export more than one UVTexCoord per vert.

Also included are the face filters and element filters, while not implimented very well, do work sometimes for smoothing out the rough edges.

dlangdev · Post by **dlangdev** » Fri Jan 04, 2008 2:41 am

yup, i got it to bake using ctrl-alt-b. though this is not using radiosity because i had to put in a lamp.

dlangdev · Post by **dlangdev** » Fri Jan 04, 2008 3:12 am

here's two textures blended now...

that is one demo, completed for baking and blending textures.

oldskoolPunk · Post by **oldskoolPunk** » Fri Jan 04, 2008 3:24 am

I didn't know about the ctrl-alt-b thanks for he tip

But to bake the radiosity solution to a texture, just click the Full Render button and hit Bake. No light required when you enable the VColLight button in the material panel. Do not add a lamp to the scene. VColLight is like adding an emit factor to the vertex colors based on the amount of light is hitting the vertex. Here is a pic of a baked radiosity solution, the texture then applied to the low-res mesh. (The one Blender's radiosity didn't run through the meat grinder)

dlangdev · Post by **dlangdev** » Fri Jan 04, 2008 3:26 am

ok, i'll try that. thanks for showing the image.

here's another, using multiply and levels adjustment.