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Daz 4 Blog - Technical Learnings etc
🕑 Added 2021-01-22 12:07:04 +0000 UTCHello again. I realise I haven't posted anything for a few days, but that doesn't mean I haven't been busy in Daz 4. In fact it's the exact opposite - I've been working around the clock. Anyway, Patreon urges you to write blogs and updates to keep your patrons informed. So, anyway, I've got some good news, some bad news, then some bad news again, then some more bad news. Then at the end of that some good news. But overall good. So prepare for a rollercoaster ride! (If you can't be bothered to read it all, skip to the TL/DR sentence at the bottom).
Good news (1) - is that I finalised Amanda's classic outfit and immediately got the urge to make a perilous scene for her. Enough waiting already! So, I spent about three hours remaking one of my favourite poses from Daz 3, then installed a grimy dungeon, sent Amanda in where immediately she was intercepted by SIX Genesis 3 goblins armed with blowpipes and tranquilizer darts. It didn't end well for Amanda and the scene pictured is with the triumphant goblins standing over our unconscious heroine and starting to strip her (I assume they were preparing her for goblin dinner?). It's an absolutely stunning scene and the lighting and textures are incredibly realistic and exactly what I was hoping for from Daz 4.
Bad News (1) - I am afraid that due to the risque content I cannot share the images here on Patreon. I am not sure whether or not they would breach rules but I cannot take the risk. Patreon rules also prohibit me uploading 'violating material' offsite and posting a link. So I won't be doing that either. I don't even know whether it's violating or not, the problem is that it's all the matter of opinion of a single unaccountable person. And I am not going back to that world of pain... I will just have to consider options. I ask people not to discuss or ask about this in comments. Move on.
Bad News (2) - The technical section. Making this complex scene has been a huge learning experience. The first thing that struck me was the incredibly long render times. Before this, the simple studio pics of Amanda were rendering 100% in 4 minutes and the iRay 'draws' were appearing in seconds. But the big 'goblin capture scene' was timing out after two hours' rendering, on 83% done. I learned to change the max render time to unlimited (it's 7200 seconds by default, d'oh) but the scenes were taking 3-4 hours to render. And the draws in the viewport were taking a minute and a half even to start - then about 10 minutes to get to any sort of half decent quality. Then, once I finally set up a 4k render and left it going overnight, I was dismayed to find it on 63% in the morning, and ended up leaving it all day, for a total of about 30 hours to finish! This was really not what I was expecting. I have a decent nVidia GTX1080 graphics card and I thought Daz would render faster than this. So, I did some investigating and found out what the hell was going wrong. The first thing I noticed was the sound - the fans on my GPU weren't spinning at all but the CPU fan was on full blast during the rendering. I looked in Task Manager and the CPU was running at 100% and the GPU at 0%. The PC was basically unusable for about a day and a half; even opening the browser took half a minute and made me worry I would crash the PC. This was not right! Clearly Daz 4 was not using my graphics card to do the render, despite the fact I had told it in render settings to use the GPU only and not the CPU. After some investigating I found a checkbox called 'Allow CPU fallback' and unchecked it. After that, I couldn't get draws or renders AT ALL - just a black screen. After updating my nVidia drivers and using the power of google, I finally found what the problem is: if the size of your scene (in GB) exceeds the memory of your video card, Daz 4 won't use it to render AT ALL. As you might imagine, this was something of a surprise and a disappointment. You would think they could program it better than that, so that the CPU and GPU could share the load. I mean, with this big scene, I might as well be using the onboard graphics of my motherboard. My GPU is redundant. What a load of crap! My video card has 8GB ram which is pretty standard for high end gaming cards, so in order to test the theory, I set about deleting things from the scene - anything that wasn't visible in the camera angle, hidden items (these all add to the memory consumption whether they are visible or not) and eventually after I had deleted three goblins... suddenly - hey presto, the graphics card spins up and it's super fast renders again. So clearly I had just managed to shoe horn the scene into the 8GB capacity of the card.
Bad News (3) - The cost. Naturally, this experience sent me scurrying to the internet to search for 16GB video cards or bigger. Actually, there aren't any of these. Almost everything is 8GB as gaming is all about the clock speed and not the memory capacity. The step up is to 'creative professional' graphics cards like the Quadro series (with 24GB) or the extremely high end gaming card the GeForce RTX 3090, also with 24GB. With this amount of video ram, I could confidently build complex scenes with dozens of figures and props. The problem is that such hardware comes at stratospheric prices. I mean, costs equivalent to the total amount I spent on building my PC. I mean, equivalent to 4-5 months' net Patreon income. And not only that, if I put a RTX3090 in this case I am going to need to upgrade my power supply from 600W to 750W, which is not enjoyable and costs another couple of hundred dollars.
Good News (2) - Overall, I am beginning to come to terms with the fact I might have to make this move. At least I understand what the problem is, and it can be addressed, at a cost. Until then, it's basically a case of struggling with CPU renders that take 8x as long and take out my PC for half a day at a time. It's pretty annoying as the main reason that I moved to Daz 4 was so I could make big complex realistic scenes with iRay lighting and use the power of my graphics card (as oppose to Daz 3 which is all a matter of CPU). So, I am giving it some thought and thinking about a financial plan to acquire the necessary hardware. In the mean time, I just have to keep scenes relatively simple/slimmed down and render no higher than Full HD.
TLDR: I need a new graphics card, it's hugely expensive, and until I get it I will have to keep scenes quite simple and/or not do high resolution renders.
Anyhow, sorry for the lack of posts, the process I have been through above took out three days of my life and was quite draining. After I have recovered I will post some nice candids and get back to work in the studio. Thanks for your ongoing support! Everythin' I do.... I do it for youuuuuu......
Comments
Torqual3D
Thanks! I am going to try all of that!
Perhaps its just the specific models that I use but when I convert them to props, it does make the vram count lower for me, even if just a little. In parameters, some models have a subdivision count that can be adjusted to reduce vram, and replacing the maps with lower resolution ones would also work.
Torqual3D
Thanks. This was helpful. I have checked here: https://www.daz3d.com/forums/discussion/comment/957806/ and the guy is saying that converting a figure to a prop doesn't reduce its GPU memory requirements for an iRay render. Is this correct? I have 16GB RAM in the machine but only 8GB VRAM. The latter is the problem.
There are many tricks to get around the v ram limitations. One I like to use is converting figures that have either high vram requirements or high def textures into props. Doing this also means you can no longer repose that figure so it might be good to have duplicates with their visibility turned off. You can also manually lower the texture resolutions in their parameters section to lower vram requirements. I usually do this for figures or objects that are placed further away from the 'camera' so it's not as noticeable. You can also render sections of the images separately and then do some post to put everything together.
