Template:Archived Page History/Warning model lightmaps: Difference between revisions

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(Redirected page to $lightmap#Limitations and caveats)
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<noinclude>'''Shows the following warnings:'''</noinclude>
#REDIRECT [[$lightmap#Limitations_and_caveats]]
 
<onlyinclude><!--
-->{{warning|Models use the same UVs for lightmaps as [[$basetexture]], and the model's lightmap is affected by [[$basetexturetransform]]; as such, lightmapping on models with overlapping or tiling UVs may not appear as intended!<br>VRAD cannot create lightmaps for UVs outside of the 0-1 UV space.<br>Additionally, shadows may appear on UV seams; this is more noticeable on lower-resolution lightmaps.}}<!--
-->{{bug|Lightmaps for models with multiple materials do not compile properly in [[VRAD]]! A lightmap will only be compiled for the first material on the model, that is a combined version of all the UV's used by all materials.<!--
    -->{{workaround|Define a pre-baked {{ent|$lightmap}} in the [[VMT]] of the [[VertexLitGeneric]] material (can be obtained using {{code|-dumppropmaps}} in [[VRAD]]).}}<!--
-->}}<!--
-->{{warning|Model lightmaps generated with [[VRAD]] are compiled as RGB888 (24-bit SDR) [[PPL]] files which can result in noticeable color banding when brightly lit in HDR mode.<!--
    -->{{workaround|<ul><li>Define a pre-baked RGBA16161616f {{ent|$lightmap}} in the [[VMT]] of the [[VertexLitGeneric]] material. A custom-coded compiler would be required to this accurately.<!-- Technically a lightmap could be baked in Blender, but that would be a pain to set up. --><li>Increase lightmap resolution (results may vary).<li>Move light source further away from the lit surface.</ul>}}<!--
-->}}<!--
-->{{warning|Models using [[$bumpmap]] cannot receive lightmaps, they will fall back to vertex-lighting based upon the models' origin or [[$illumposition]].<!--
    -->{{note|There is an in-engine check that confirms whether or not the {{ent|$bumpmap}} parameter is defined for a material, a custom shader cannot simply use both as there are a dozen technicalities that have to be overcome.
 
{{Expand|noborder=1|title=Technical|
If {{ent|$bumpmap}}, {{ent|$normalmap}}, or {{ent|$phong}} is defined, the engine will not send the lightmap data to the shader.<br>
For $bumpmap, a workaround for this is to use a differently named parameter. ($NormalTexture) to get the normal map and undefining $bumpmap.<br>
However no static lighting data can be received by the shader, if the $bumpmap parameter is not set to anything. This refers to lights that are not named and are not inherently dynamic.<br>
This may be prefered as the static light information is '''already''' prebaked in the lightmap, however it means you cannot receive direction information from the lights.<br>
No light direction means no bumped lighting from the lightmap. Aka no specular highlights.<br>
A fix for this would be modifying [[VRAD]] to spit out a lightmap that is *2 the size on the U axis and then storing an average light direction there or doing some other smart technique to 'memorize' light directions.
 
This in-engine check also exists for $phong, however getting around the issue is more tricky. The default value of the integer parameter will be 0 even if not set in the [[vmt]]. Thus making $phong always be defined in a way.}}}}<!--
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Revision as of 06:56, 5 September 2024

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