Lightmaps with models

[lukesmith]

I understand that gtkradiant will calculate shadows cast by models (md3, obj, etc) during the lighting phase. I was just wondering, will gtkradiant also create a lightmap for the model? using the uv coordinates of the model, so that static models can all be lit in the same way as the level geometry?

[DaEngineer]

You have to add the key "spawnflags" to the model via the entity menu (N-key while model is selected) and give it a value of "4".

[obsidian]

Just beware that most models will actually look better vertex lit. Lightmapped models only look good on models with large planar surfaces like terrain. First, lightmaps are projected axially; second, on most models with a relatively high level of tessellations and vertexes will actually have a better lighting fidelity than a comparatively lower resolution lightmap.

[lukesmith]

I was thinking along the lines that if all static models are lightmapped I can gain even more speed by not having to calculate lighting for them and not having to calculate shadows they recieve from the level geometry. Ill try using a larger lightmap size for models and see how it looks.

[obsidian]

Errr... vertex lighting is less system intensive than lightmaps. That's why Q3 has the option to turn off lightmaps and revert to vertex light only on lower end (circa 1999) systems.

[lukesmith]

Im not doing this for quake3 but for a renderer that I have developed. So I thought it worth experimenting with lightmapping the staticmeshes otherwise any shadows that fall on the staticmesh would have to be calculated in realtime.

[obsidian]

Ah, I see.

You may also need to play around with q3map_shadeAngle and q3map_lightmapMergable in the shader.

[lukesmith]

Oh great thanks.