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Topic: Using CG_Trace

torhu
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Joined: 16 Jun 2005
Posts: 76

Posted: 10-29-2005 10:57 PM

Code:
void CG_Trace( trace_t *result, const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end, int skipNumber, int mask ) {

I think I understand the rest, but what do the mins and maxs parameters do?

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corncobman
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Joined: 07 Aug 2003
Posts: 1902

Posted: 10-30-2005 04:33 AM

It specifies the width of the trace, rather than trace using a line, you can trace with a particular size, and if the sides hit whatever you are tracing for, it will stop.

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^misantropia^
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Joined: 12 Mar 2005
Posts: 3958

Posted: 10-30-2005 06:09 AM

Think of it as doing a sweep with a bounding box.

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torhu
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Joined: 16 Jun 2005
Posts: 76

Posted: 10-30-2005 04:41 PM

I figured that mins and maxs would specify a box, but I'm not quite sure exactly how. Could someone draw me some ascii art to show?

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^misantropia^
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Posted: 10-31-2005 03:38 AM

Think of the player's bounding box, which is 32x32x64 or (-16, -16, -32)-(16, 16, 32). If you run in a straight line, you're bound to bump into something solid sooner or later. Now that's exactly what CG_Trace() does.

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torhu
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Joined: 16 Jun 2005
Posts: 76

Posted: 10-31-2005 06:46 PM

Thanks. Somehow it didn't occur to me that mins and maxs are actually vectors, not single values. Think I've got it now.

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Code:void CG_Trace( trace_t *result, const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end, int skipNumber, int mask ) { I think I understand the rest, but what do the mins and maxs parameters do?

It specifies the width of the trace, rather than trace using a line, you can trace with a particular size, and if the sides hit whatever you are tracing for, it will stop.

Think of it as doing a sweep with a bounding box.

I figured that mins and maxs would specify a box, but I'm not quite sure exactly how. Could someone draw me some ascii art to show?

Think of the player's bounding box, which is 32x32x64 or (-16, -16, -32)-(16, 16, 32). If you run in a straight line, you're bound to bump into something solid sooner or later. Now that's exactly what CG_Trace() does.

Thanks. Somehow it didn't occur to me that mins and maxs are actually vectors, not single values. Think I've got it now.

Code:
void CG_Trace( trace_t *result, const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end, int skipNumber, int mask ) {

I think I understand the rest, but what do the mins and maxs parameters do?