GU_TextureUtils.h File Reference

#include "GU_API.h"
#include <SYS/SYS_Types.h>

Include dependency graph for GU_TextureUtils.h:

Go to the source code of this file.

Functions
GU_API bool	GUfixVertexTextureSeams (GU_Detail &gdp, fpreal uv_span=0.25, const char *attrib="uv", const GA_PrimitiveGroup *group=NULL)

Function Documentation

GU_API bool GUfixVertexTextureSeams	(	GU_Detail &	gdp,
		fpreal	uv_span = 0.25,
		const char *	attrib = "uv",
		const GA_PrimitiveGroup *	group = NULL
	)

GUfixVertexTextureSeams() will look for "seams" uv's and try to fix them.

Seams in textures occur when the texture coordinates "wrap" in periodicity. For example, when doing polar mapping, at one meridian, the u-coordinates will go from 0.9 to 0.1. So, in this case, rather than mapping from 0.9 to 0.1, the texture engine will interpolate between .1 and .9 and the entire map will appear (reversed) in that span. This code simply looks for faces which have a delta in coordinates larger than the uv_span passed in and will then attempt to fix this by adjusting coordinates. In the above case, the coordinates would be set to either (-0.1, 0.1) or (0.9, 1.1).

This is only applicable to vertex texture coordinates since point textures are shared between primitives and fixing for one primitive would likely break another primitive (which shared points).