I recently saw a video on youtube, showing a Map that mostly consisted of models with baked light and textures, only reflections and gamemechanics are truely done by source, the result is a stunning graphical quality!
(Search for: Using Vray with Source).
I wanted to try out this way of mapping and here's what i experienced and how i made it working.
Consider this tutorial as a list of tips/hints, it is for people who are experienced with mapping/modelling.
I done the Modelling/Lighting in Blender and exported everything to Source with kHED.
-you need to create the complete visual geometry of your Level in your modelling program, so keep attention at scale and walkability.
-the Models need propper UV-maps, since we are going to bake high-detailed lightmaps as well as Diffuse textures.
-group the models and their UVmaps based on their size to keep the lighting-detail at a consistent level
-create reasonable collisionmeshes, not to detailed and not to undetailed
-don't forget to model lightsources
Second Step: Lighting the Scene
I baked the rendered lighting in Blender.
-set up the lighting as you want it to be in the map and bake it together with the diffuse-channel to an at least 2048*2048 sized texture
-too small-scaled and unconsistent UV maps end up in bad bake results
-only use texture/material/rendering technics that source supports or that are bakeable to the diffuse channel -> diffuse/bump/specular/AO/shadows. Shadows and AO will be baked to the diffuse channel and therefore won't be much different from what you see in your render before exporting.
Third Step: Exporting
I done that with kHED, since it gives you a good preview of your goemetry/diffusetexture
-Compressing the texures can reduce the quality of the baked light, so only do it for textures that won't look too bad with compression or to reduce the filesize
-try to group the geometry by material type and combine their uvmaps if the material effects are important. if not, group your geometry by more practical matters, like the size/cubemap-use.
-keep the model's positions after seperating them in your modelling program or they wont fit together well, in short: only use one origin for one map or room, depending on the size
Fourth Step: Mapping
It will differ from the normal workflow, since you have already created your lightmaps and your geometry.
1. Place your Models as static-models, adjust them so that they fit together, don't be too lazy to change and reimport your stuff until it looks good
2.Create an brush hull around your models, it should sit tight to give vvis some information on how to create the vis-leaves.(but don't let it intersect the model-geometry)
Choose a Simple texture/nodraw For your surrunding brushes and give them a veeeeery high lightmapscale since your not going to see them at all
3.Create an Lightbox to give your static-model an consistent, uniform and smooth white lighting which doesnt change the model's texture brightness and colour, you can compare mat_fullbright 0 and 1 to fine-tune your lightbox ;) make sure to not enable any kind of vertex lighting for your static geometry
4. Add lights/glows that simulate the lights used in your renderer, so that the physics-props, player models, and view-models are correctly lit and fit to the scene
5.Add cubemaps and all the other needed entitys, but dont let them intersect the physboxes of your "map-models" since they will fall through when placed into the physbox
Thanks for your attention, i hope this helped you to realise a "map made of models"