I’m writing an add-on to generate impostors. It’s a lot like baking, but more automated. Code here.
You build a low-detail box around your object, and, like baking, it renders the object from the normal to each face of the low-detail box, then pastes that on the low-detail box. Intended use is Second Life low-detail models.
It’s mostly working, but the lighting intensity is off in Blender rendering mode. I’m using an area light positioned at the camera, with the area light sized to match the face size. Far too dim for large areas. Tried increasing the energy by a multiplier based on the area. That didn’t work right either.
Is there an easy way to do this? What I really need is diffuse light from all directions and no shadows. Has to work for both Blender and Cycles renderer, although the code can do special cases if needed.
For your model material you’d connect the diffuse color to an emission bsdf. The emission bsdf goes into the output node. Emission strength should be set to 1. This is for Cycles.
For Blender internal I think thid was an option called shadeless. Not sure though.
The emission bsdf trick I use in Rhino 3D to get what they call self-illumination.
Yes, modifying the input model to be emissive only would work. This is an add-on to make low-rez impostors of existing models, though. I have to take the input model as given. I can change the lighting and camera parameters. All I really need is diffuse lighting from behind the camera, aimed forwards with no falloff. The problem is getting constant intensity. A sun is too directional. Area lamps are a step in the right direction, but how do I get constant intensity regardless of size?