Splotchy colors

jdavison67

I've tried everything I can think of...but when I render I get these splotches in my texture.

What causes this???

 

barbult

Is this an Iray render? If so, try increasing the vaules for Texture Compression on the Advanced tab in the Render Settings pane. Increasing the numbers will take more memory in your graphics card, so don't get too carried away.

jdavison67

Thanks!

I'll give it a shot.

 

 

jdavison67

My compression was set really low so I just bumped it up a bit, but I am still seeing the splottches.

I found I could reduce it a lot by turning off the emboss FX on the web texture in Photoshop...it doesn't look as slick, but the splotchyness is greatly reduced.

I'm using normal maps, and no bump maps for this, not sure if that matters.

barbult

How high did you bring the compression up? You may need to try a higher setting. I had a problem exactly like what you show in your image. In my case it was on the red texture for the hoodie in the Mall Girl for Genesis 3 Female(s). The area of high contrast between the red fabric and the white stitching was splotchy until I raised the compression setting. In these two renders, the only thing I changed was the compression setting. Examination of the texture file itself showed absolutely no splotches, so I figured it was a render issue and not a texture issue.

jdavison67

I see...

I will try it again as I'm seeing this in other renders.

 

I changed the setting in the same location you did, I just did not go as high with it, as the highest of my two graphics cards is only 4 gig.

I couldn't imagine letting it max out on this single texture.

 

Thanks for the advice!

jdavison67

I see...

I will try it again as I'm seeing this in other renders.

 

I changed the setting in the same location you did, I just did not go as high with it as my the highest of my two graphics cards is only 4 gig.

I couldn't imagine letting it max out on a single texture.

 

Thanks for the advice!

jdavison67

Ok, I found a setting that worked!

 

Thanks!

jdavison67

Here is the other one.

Much better!

barbult

If you have both graphics cards selected in the render settings, your GPU rendering will be limited by the memory of the SMALLEST card, because the scene must fit in BOTH cards . If one is 2 GB and one is 4 GB, your render will switch to CPU if your scene exceeds 2 GB. Using both cards is only beneficial if your scene is small and fits in the 2 GB memory space. You may be better off running your monitor on the 760 and not selecting it in the render settings, if you regularly create scenes that don't fit in 2 GB (or whatever that 760 has for GPU memory). This might be wrong - see below.

Setting texture compression to 4MB should not max out a 4 GB GPU. Try a render with compression on 4096 and only the 960 selected. See what results you get.

Edit: I typed this before I saw your image at compression 4096. The advice about the 2 graphics cards stands, though.

Edited to strike out info that might be wrong.

barbult

jdavison67 said:

Here is the other one.

Much better!

Looks good. Now your challenge is to remember that this is what fixed it next time you run into that problem.

mjc1016

barbult said:

If you have both graphics cards selected in the render settings, your GPU rendering will be limited by the memory of the SMALLEST card, because the scene must fit in BOTH cards . If one is 2 GB and one is 4 GB, your render will switch to CPU if your scene exceeds 2 GB. Using both cards is only beneficial if your scene is small and fits in the 2 GB memory space. You may be better off running your monitor on the 760 and not selecting it in the render settings, if you regularly create scenes that don't fit in 2 GB (or whatever that 760 has for GPU memory).

Setting texture compression to 4MB should not max out a 4 GB GPU. Try a render with compression on 4096 and only the 960 selected. See what results you get.

Edit: I typed this before I saw your image at compression 4096. The advice about the 2 graphics cards stands, though.

Actually, it works on a card by card basis...so if the scene is 2.5 GB it will still use the 4 GB card, but not the 2 GB card....

barbult

mjc1016 said:

barbult said:

If you have both graphics cards selected in the render settings, your GPU rendering will be limited by the memory of the SMALLEST card, because the scene must fit in BOTH cards . If one is 2 GB and one is 4 GB, your render will switch to CPU if your scene exceeds 2 GB. Using both cards is only beneficial if your scene is small and fits in the 2 GB memory space. You may be better off running your monitor on the 760 and not selecting it in the render settings, if you regularly create scenes that don't fit in 2 GB (or whatever that 760 has for GPU memory).

Setting texture compression to 4MB should not max out a 4 GB GPU. Try a render with compression on 4096 and only the 960 selected. See what results you get.

Edit: I typed this before I saw your image at compression 4096. The advice about the 2 graphics cards stands, though.

Actually, it works on a card by card basis...so if the scene is 2.5 GB it will still use the 4 GB card, but not the 2 GB card....

Is that a recent change? I read many times in the forums that it was limited by the smaller card.

mjc1016

barbult said:

mjc1016 said:

barbult said:

If you have both graphics cards selected in the render settings, your GPU rendering will be limited by the memory of the SMALLEST card, because the scene must fit in BOTH cards . If one is 2 GB and one is 4 GB, your render will switch to CPU if your scene exceeds 2 GB. Using both cards is only beneficial if your scene is small and fits in the 2 GB memory space. You may be better off running your monitor on the 760 and not selecting it in the render settings, if you regularly create scenes that don't fit in 2 GB (or whatever that 760 has for GPU memory).

Setting texture compression to 4MB should not max out a 4 GB GPU. Try a render with compression on 4096 and only the 960 selected. See what results you get.

Edit: I typed this before I saw your image at compression 4096. The advice about the 2 graphics cards stands, though.

Actually, it works on a card by card basis...so if the scene is 2.5 GB it will still use the 4 GB card, but not the 2 GB card....

Is that a recent change? I read many times in the forums that it was limited by the smaller card.

I'm going to have to look through all that...but I think it was Spooky that explained it best....

I can't find the specific post, but the general pattern I've come up with is that if you have a 4 GB card and 2 GB card they will render like this...

Iray will use both cards if the entire scene fits on both.

It will drop the smaller card if the scene is over what is available on it (if it's driving the monitors, too, then it will be less than 2 GB).   It will just use the 4 GB card.

If the scene is larger than 4 GB it drop to CPU only.

barbult

I only have one card, so I can't verify it myself. It sounds like I may have been spreading misinformation. Thanks for coming along to straighten things out.

PS. Attempting to search the forum to find any references to what I believe I read was fruitless. Even with Google search, I couldn't put together a search that was useful.

mjc1016

barbult said:

PS. Attempting to search the forum to find any references to what I believe I read was fruitless. Even with Google search, I couldn't put together a search that was useful.

I was running into the same thing...Spooky has posted so much it was hard to pin it down.

 

jdavison67

Thanks guys, yes I figured my scene was under 2 gig as I just had the one character...

Usually I only use the 960 for the,scene and the 760 for monitor.

I really need to get a 6gig with more cuda cores, but that's for another time.

 

MEC4D

if the scene ram is higher than the lower card ram it will skip the card for rendering and use the second  with bigger capacity if both are selected , I made tests with 2 Titans 12 gb and gtx 760 2gb

Iray actually not use all the cuda cores on both card even if this use the same v-ram from both , usually 1 card is used more heavy than the other so having 3 cards not exactly mean 3 x the speed even if it looks like 

the same  in Blender , only Octane use full power of more cards if there is more used for rendering it have to do with the iray software  .

If your scene is 2GB then all cards need to support it to be used and at last 4GB of physically RAM per card so if you have 2 cards that going to render  2GB scene you need 4 GB physical Ram for the cards only not including system , not to mention ram needed for rendering the image itself depends of size , how higher the resolution how more v-ram going to be used too

Iray store the 2GB scene on the card , then need additional  v-ram and physical ram  to produce the image too ..

what I did before when I had just 2GB card and less ram was , starting the rendering with 20 pixel samples then stop it without closing, removed the view port scene in DS and load empty default and then resumed the rendering again changing the samples to whatever I needed , it free the v-ram on your card and ram system so I could render better quality using just GPU and increased  samples

barbult said:

mjc1016 said:

barbult said:

If you have both graphics cards selected in the render settings, your GPU rendering will be limited by the memory of the SMALLEST card, because the scene must fit in BOTH cards . If one is 2 GB and one is 4 GB, your render will switch to CPU if your scene exceeds 2 GB. Using both cards is only beneficial if your scene is small and fits in the 2 GB memory space. You may be better off running your monitor on the 760 and not selecting it in the render settings, if you regularly create scenes that don't fit in 2 GB (or whatever that 760 has for GPU memory).

Setting texture compression to 4MB should not max out a 4 GB GPU. Try a render with compression on 4096 and only the 960 selected. See what results you get.

Edit: I typed this before I saw your image at compression 4096. The advice about the 2 graphics cards stands, though.

Actually, it works on a card by card basis...so if the scene is 2.5 GB it will still use the 4 GB card, but not the 2 GB card....

Is that a recent change? I read many times in the forums that it was limited by the smaller card.

 

barbult

Thanks for testing and for the clever resume trick with the empty scene.

xialiubei

Thank you, Barbult.  Was having a similar issue with a render, and your advice worked perfectly.

barbult

Great to hear that it helped another user!

Jpeger

I had a similar problem, I loaded the texture into Photoshop and made the PPI 300 (from 72), and it stopped the blotching.