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Crazy Scanline AO ideas

Posted: Sat Aug 14, 2004 10:54 pm
by JA-forreal
I was thinking of a way to create an effect of diffused light shadows similar to AO for the raytracing but specifically for non raytraced spot lights. I have done test in which I parented grids of low power negative lights to the surfaces of objects. Then I set up either spotlights or a hemilight system. The shadowing effect are similar to AO lighting but without the rendering time hold ups.

I am not a coder but I was wondering if there was a way to access the vertex level mesh topology of objects and set in place a feature that would set a spotlights, etc. "negative" shadow depth value for light that is cast onto the surface of a mesh object. This setup could control how much light and shadow actually reaches the mesh surface to illuminate it. This value (negative to positive light level strength per vertex, calculated by the characteristics of the light properties) could be random or logical based on the distance of the light from the surface and the length of the lights shadow depth. Maybe the vertexes could be set with this value at rendertime and the diffused deep shadowing effect would be seen upon rendering. This would be better than manually applying negative lights to grid on a mesh surface to simulate AO lighting setups with scanline renders.

Maybe it's a 3d artist crazy idea, I'm no coder.

What do you think about this?

In any case,

Blend on!

Re: Crazy Scanline AO ideas

Posted: Sun Aug 15, 2004 12:15 am
by z3r0_d
JA-forreal wrote:I was thinking of a way to create an effect of diffused light shadows similar to AO for the raytracing but specifically for non raytraced spot lights. I have done test in which I parented grids of low power negative lights to the surfaces of objects. Then I set up either spotlights or a hemilight system. The shadowing effect are similar to AO lighting but without the rendering time hold ups.
people have been doing that in blender for a long long time
[I wish the community journals were common reading...]
JA-forreal wrote:I am not a coder but I was wondering if there was a way to access the vertex level mesh topology of objects and set in place a feature that would set a spotlights, etc. "negative" shadow depth value for light that is cast onto the surface of a mesh object. This setup could control how much light and shadow actually reaches the mesh surface to illuminate it. This value (negative to positive light level strength per vertex, calculated by the characteristics of the light properties) could be random or logical based on the distance of the light from the surface and the length of the lights shadow depth. Maybe the vertexes could be set with this value at rendertime and the diffused deep shadowing effect would be seen upon rendering. This would be better than manually applying negative lights to grid on a mesh surface to simulate AO lighting setups with scanline renders.
uhh, somehow I don't get your idea

it just doesn't make sense

you can store things in vertex colors and do a couple things with materials, but you can't store like reflectivity [you could however mess with the normal to create some interesting effects].

so, are you trying to come at a way to get subsurface scattering using buffer lamps?
[other apps have ways to do it, by essentially using the depth map of the lamp in a shader...]

Posted: Sun Aug 15, 2004 3:00 am
by JA-forreal
I'm taking this idea from how negative lights are used to limit the amount of light that is shot from a spotlight. This effect can create lighting that is similar to GI lighting.

Or you can do fake area lighting effects with negative lights.

I was just thinking that you can duplicate this effect over the surface of a mesh but have the vertexes act like mini negative lights that are duplicated over the mesh surface. Then the spotlight's lighting effect on the mesh can be controlled by this array of vertex level negative lights.

Maybe the spotlight's area of influence determined which vertex level negative lights were active or not. If the light didn't affect an area of the mesh surface the vertex level negative lights would be totally black. The areas that the spotlight affected from the starting point of the light to the falloff point of the light could activate the vertex level negative lights which would limit the way the light responds to the mesh surface. I hope that this makes more sense. I would like to see some type of AO feature for Blenders Scanline rendering if possible.

Blend on!