lightcache processing very slowly

[stevesideas]

Hi there,

I have a new problem. Ive just created a large grass texture. It also has displacement applied to it. When the lightcache is being calculated cpu usage only goes to about 13% usage. I have dynamic memory set to auto & 2500mb and I have 6gb of ram. Also lightcache passes set to 8.

Any ideas ?

[stevesideas]

Update: I just restarted max and the lightcache processing is fine...what is happening. I did open photoshop to tinker around with the texture (which is about 10000x6000 pixels). Do you think there may be memory issues. I dont use bitmap pager...is this something that could help? I dont even know what it is used for..

[stevesideas]

ok. I did a search, as I remembered somewhere about being able to clear the cache in max. The cache clear didnt work: gc(), but freeSceneBitmaps() did work. Not sure why the lightcahce is struggling at times. I wonder if it is because photoshop is using memory and vray is struggling to find the memory to do the light cache efficiently ?

Vlado ?

[Morbid Angel]

well, typically if you are rendering displacement, any processing will take longer, since if you are using a 3d displacement, the preprocessing will take extra time (for displacement) calculation and is not multi threaded. But if you are using 2d displacement, there could be something else.

[stevesideas]

I am only using 2d displacement. I have resized all my extra large textures (10000x6000 pixels) to half size and that seems to have improved it somewhat. My cpu sitting at 2% whilst it trys to process the displacement is a long way short of 1 cpu at 100%. It seems to definately be linked to memory. Each time I clear the bitmaps and they reload (especially after using photoshop to tinker around with some textures), it works fine. If I dont do that, it is a much much longer wait.

[Morbid Angel]

what are your displacement settings? also why are your textures so large?

[stevesideas]

I was trying out extra large grass textures (taken of my garden) stitched together to reduce the amount to tiling. Basically the texture covered a larger area so less need to tile. My displacement settings are pretty default apart from the amount. I have the dynamic memory set quite high also.

[3DMK]

Mix Material

To try & conserve memory you could try a mix map on two smaller textures.

Materials/Map types/MIX

Simply use two different bitmap grass textures & mix them together with a max procedural noise map. Because the noise map does not repeat [because it's computer generated to always be random] you get a nice NON-TILING texture. Make your noise map black & white. Black will be tex1 & white will be tex2.Use the noise map tweaks to control how it blends.

Not sure how mix maps go with displacement though?? Fast--slow?? Anyone else know??

Also remember to have your grass mesh as a nice & clean quad mesh. And the more your mesh is subdivided the less work vray has to do [no big & uneven triangles.]

Hope this helps

[natty]

Hi

sometimes we turn Displacement off for the LC calcs, save the LC, switch to from file then turn Displace back on for the IRR map cals ... seems to work fine..

N