Textures killing render time?

[Intenzity]

Its come to my attention that alot of my textures really hurt the rendering times. Mostly what happens is we scan the fabric at about 200 or 300 dpi. Obviously the file would be large but even sometimes after photoshopping the image and saving it as a .tif at around 512x512 to keep the image file size small, the rendering comes to a screeching halt. A sofa for example would take about 30 sec. to render with a default vray shader. Once a bitmap is added it takes about 9min. We do apply cropping and maybe turn down the blur so we can see the detail more. (Usually we drop it to .5 at max .1) Is there something we're doing wrong in going about setting up textures?

Thanks in advance

-Andrew

[cocolas]

well, you can always have them at 150dpi instead of 200 or worse 300.....

[Intenzity]

So in essence does the scanned in resolution really have that much of an impact? Will a texture bitmap lets say at 512x512 image size at 200 dpi signaficantly be slower than a bitmap at 512x512 image size at 150dpi?

-Andrew

[cocolas]

from my experience...yes!.....and w/out notisable quality in the render....

for arch viz, I usually don't go higher then 150, unless it's a huge texutere for a large site plan or terrrain texture....for regular stuff I keep at 15o or lower...

paul.

[Dynedain]

So in essence does the scanned in resolution really have that much of an impact? Will a texture bitmap lets say at 512x512 image size at 200 dpi signaficantly be slower than a bitmap at 512x512 image size at 150dpi?

-Andrew

shouldn't...they're the same number of pixels

i think that cocolas meant you could go with a smaller image

make sure those tifs are RGB, not CMYK...they'll be smaller in size and memory
maybee if they are uncompressed tif they'll be loaded faster?

[cocolas]

[quote]

i think that cocolas meant you could go with a smaller image

[quote]

that's what I meant...



paul.

[Intenzity]

Thanks for the replies, now i'm geared in the right direction to experiment a little for optimal settings

-Andrew

[digitalx3d]

Ummmm...shouldn't DPI have no affect on this at all? I mean, DPI has no affect on file size because it is dependent on the dimensions of the image. It is the total number of pixels that you need to be worried about. Another thing to consider is whether or not your .tif files are saving an alpha channel in them. However, just in general, I think .tif files are slower than jpgs. At least in the material editor. I'm surprised it is affecting your render times.

John Pruden
Digital-X

[Intenzity]

Ummmm...shouldn't DPI have no affect on this at all?

Dynedain clarified that by saying its the image size not the dpi amount.

I'll have to check my .tif settings but I think I don't save it with an alpha. There's a couple other things I'll try.

Thanks.

-Andrew

[flipside]

Its very normal that rendering a simple one color material is faster than a textured one. The AA has much more work on the texture than if it was just simple color. If the texture is fine (even with a tiled 10*10px map) it will slow down rendering a lot. I even think IR calculation is affected a lot by it, because the bounced light has much more variety in color coming from a texture than coming from a single colored material.

[Intenzity]

I even think IR calculation is affected a lot by it, because the bounced light has much more variety in color coming from a texture than coming from a single colored material.

That's a very interesting point because now I'm curious if I turned off generate GI on all furniture would it increase the render times significantly. Although furniture does bleed color in real life its almost minimal depending on the size. Usually color bleeds are found noticably in floors, walls, ceilings, and transparent curtains for example.

-Andrew

[flipside]

yes but it's not only the bleeding you want, if you turn send GI off, areas underneath the furniture will become darker because there's no bouncing of light.

[Intenzity]

ah good point, I'd have to experiment to see how dark it gets because sometimes contrast is nice, but too much is not good. That or fake in some light. Again more experimenting but all for the sake of speed rendering

-Andrew

[f97ao]

Guys I got a good idea for the sofa perhaps. Why not create a copy of the sofa with just a standard material and use GI for this, But then you have a sofa with texture that is a little big larger but don't use GI.

That might speed it up alot, since gi is simpler, but it would look similar.
/Phoibos

[flipside]

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.