Textures killing render time?

[DP]

this sounds very odd...we work with textures in the 1000's of pixel range, not 100's and although theres a slow down when theyre applied its nothing like a jump from 30 sec to 9 mins, even when using supersampling and very low blur. Low amounts of RAM?

fyi DPI will make no difference if your pixel amount is the same...512x512@300dpi is exactly the same size file in ram as 512x512@72dpi or 1000dpi for that matter.

To judge the amount of pixels x by y you need, just simply render out the area you need to texture with a map and measure it in photoshop. Remember to work it out properly if you tile your bitmap or are indeed cropping into it.

[flipside]

Well I just did some tests, a teapot on a plane, and skylight and GI turned on.

The texture didn't seem to matter much on the GI calculation. Even with high clr treshold it didn't make any difference. (i tried various kinds of textures - and different blur parameters)

The rendering itsself was influenced more by the texture. The untextured version took 52sec.

A fairly simple texture without too much color variation added 10 sec to it. Blur from 1.0 to 0.1 added another 20sec. So that's 50s untextured and 80 sec with texture blur0.1.

A more colored detailed texture took 83sec with blur 1.0 and 120sec with blur 0.1. So rendertime more than doubled by adding one texture with blur 0.1.

I can imagine a scene with much more textures and bumps and times will go up much more compared to a non textured version.

A checker map in the diffuse took 96sec (very high tiling) and had heavy moire patterns...

[DP]

yes, theres an appreciable drop when textures are added, i guess thats the antialising penalty for starters....30 secs to 9 mins though sounds odd...thats the sort of kick i would expect glossy reflections set on 50 to give.

even with hammersley supersampling on a 0.1 blurred map its not that big a drop. But i realise that adding falloffs, specular and bump may slow it down more.

Intenzity - perhaps post a shot of your material, lets see if theres anything nasty in there thats slowing it down.

[Intenzity]

I'm finishing up some changes to a project, but hopefully soon I'll post the texture image and the max file for others to see, maybe I just have real goofy settings

-Andrew

[J_Bug]

That's what someone mentioned a while ago that brazil can do. You can assign a different mat for GI calculation, so you could also reduce color bleeding etc. I would like to have this in vray too, so you could assign a simple color mat to the 'GI-channel' and still have a complicated texture on the actual mat.

I remember this feature from Brazil Beta and it was very useful. Don't know if it's changed any since I last used it. It worked as a check box in the render params and allowed the GI to use the diffuse color swatch as a flat color override. It would be a great solution for color bleed as well as a nice little speed tweak. We should suggest it in the wish list.

--Jon

[DP]

yes it would be useful...very...being able to cheat bounce saturation would be very handy