Re: Help! Flickering textures
Angus Dorbie (dorbie++at++bitch.reading.sgi.com)
Mon, 14 Aug 1995 11:58:46 -0600
On Aug 14, 5:10pm, Terence Ker wrote:
> Subject: Help! Flickering textures
>
> Dear Performer friends:
>
> I used naive way to make a large grass land, completely flat, by
> making use of the Triangle strip pfGeoSet and apply a texture 256x165
> on it. It looks good at the near but the textures seemed to be squeezed
> at the far, flickering and crawling.
>
> I attach a pfGeoState to the pfGeoSet. Inside that pfGeoState,
> I used the following attributes:
>
> grass_tex = pfNewTex(vgGetSharedArena());
> pfLoadTexFile(grass_tex, "grass.rgb");
>
> pfTexFormat(grass_tex, PFTEX_INTERNAL_FORMAT, PFTEX_RGBA_8);
> pfTexFormat(grass_tex, PFTEX_EXTERNAL_FORMAT, PFTEX_PACK_8);
> pfTexFilter(grass_tex, PFTEX_MAGFILTER, PFTEX_BILINEAR);
> pfTexFilter(grass_tex, PFTEX_MINFILTER, PFTEX_BILINEAR);
> pfTexRepeat(grass_tex, PFTEX_WRAP, PFTEX_REPEAT);
>
> Is this the problem of "projected textues" which I have seen quite
> frequently discussed in this mail group? How should I solve the problem?
> by MipMap? HOw?
>
>
>
>
> -= Terence Ke =-
>
> Systems & Technology
> Taipei, Taiwan
> e-mail: terence++at++systech.hinet.net
>
>
>
>
>-- End of excerpt from Terence Ker
Yes your correct, MipMapping will solve this, it's a problem with your
minification filter and has nothing to do with projected texture.
pfTexFilter(grass_tex, PFTEX_MINFILTER, PFTEX_MIPMAP_TRILINEAR);
look at the manual page for texdef.
You should also use,
pfTexFormat(grass_tex, PFTEX_INTERNAL_FORMAT, PFTEX_RGB_5);
to speed rendering and save texture memory if the bit loss doesn't mess up
your image quality too much.
--
Angus Dorbie,
Silicon Graphics Ltd, UK
dorbie++at++reading.sgi.com
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on Mon Aug 10 1998 - 17:51:47 PDT