View Full Version : Shadow resolution

edd max
11 November 2003, 11:19 PM
When i render an image with a 10,000 shadow map size, appears a message telling insufficient memory for shadow buffer.
how can i change the volume of memory that the software uses for the shadow because i have plenty of memory.

thanks edd max

11 November 2003, 10:29 PM
Well Edd max. 10000 is a awfully big shadow map!
Could you try using a few lights with smaller shadow maps or a raytrace light. What type of scene are you lighting? Is this 10000 shadow map sunlight by anychance illumating a outdoor area? Not sure if or how you can change the 'volume of memory' allocated to specifically shadow maps.

11 November 2003, 08:01 AM
Most feature film work is done with shadow maps of 512 and 1024. 2048 is used when really needed. Of course some lower (128, 256) and higher (8096 is considered crazy) resolutions are used in special cases.

Dmap resolutions that aren't a power of 2 are usually rounded up, so 10,000 would internally be 16,384 in most renderers. 16384x16384 x 4 bytes per sample for a floating point value would be a 1 GB map - it would take much more than 1 GB RAM to compute the map and use it in your render, though.

Usually if you are tempted to go into crazy shadow map resolutions it means you should re-think your shadow casting approach, and split your shadowing into more maps that are better focused around your subjects. If you have a scene that's hard to render in one pass, render some layers and shadow passes separately to keep render times reasonable.


12 December 2003, 01:06 AM
Or consider using raytraced shadows or an arealight, since they won't hit that sort of memory limit.

- Neil

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