Particle/Material Help

[Anonymous]

Hello,

I was wondering if someone could help me with a problem I'm having. I have particles that I want to be smoke, but the material I'm using is just awful. It renders as squares the majority of the time and the colour is off as well. If someone could help me get the particles to render a nice smoke like shape (not that I know what type of shape that is!). I would like them to start of light greyish, then go to dark grey and then black over their life but because I have particles spawning and dying all at seperate times, I'd be happy if they can just stay a darkish grey colour. I have a pretty tight deadline for this so any help would be much appreciated and the quicker the better! I've attached a 2010, 2011 and 2012 version of my file so feel free to open it up and have a look. Just a heads up though, there is a lot of particles in the file so performance might be a bit of an issue.

Thanks,

Jack

pre_rendered_scene2010.zip

[Anonymous]

Try it on your end and see if the flames render. I just turned off the keep aparts in the PF Turbulence system, not any others. But from the frames I rendered, I think it looks the same. It might only be one of the keep aparts, I didn't have time to narrow it down. I wouldn't be surprised if it was just the keep apart using the PF Flames system because the high amount of particles in that system.

[Anonymous]

I've just tried rendering a few frames I had problems with through the render farm on one computer and it worked fine so what I'm thinking about doing is letting the render farm finish the job that's already been submitted and then either rendering the frames where the fire has disappeared on one computer or resubmitted the frames to the render farm again.

Thanks for all your help...again!

Cheers

[Anonymous]

Right so I tried rendering some frames I was failing on and at the beginning they all worked fine by just re-rendering them and not turning anything off so that was good. Then I got to about 500 frames ish and the fire wouldn't render until I turned off the keep apart operators in the PF Turbulence pflow. Then that worked for awhile till about 800 frames when the fire wouldn't render again so I turned off all the keep aparts in all the fire pflows apart from the main PF Flames one. This worked for awhile until I got to abotu 1100 frames and then it stopped again. I'm running out of options here because I can't turn off the keep aparts in the main PF Flames pflow because they fire looks awful. Turning them off in the other 3 barely affected the fire so I can afford to turn them off.

Thanks,

[Anonymous]

One more quick question as well that is completely off topic, if I go back to Max 2010, does it have the iray renderer? I want to get into some photorealistic modelling and texturing and I've been told that iray would be the best to do that in.

[Steve_Curley]

Nope. Introduced in the 2011 Advantage Pack for subscription users.

[Anonymous]

Ah well. You can get good results just using mental ray anyway can't you?

[Anonymous]

I can look at your file more later to see if there's another problem area, but until then here's some thoughts.

If your fire renders with the smoke turned off, you can render the smoke separately and composite it afterwards. Or if you can lower the particle count of the flame system and maybe increase the shape size, the blobmesh might look similar and you'll have less calculations for the keep aparts. If krakatoa is an option still, you can try that route and cache the particles out which might solve the problem.

And you can get great results with mental ray, it's just about learning how to use it correctly.

[Anonymous]

What I'm going to do for the time being is just let the render farm keep going and just render the failed frames (the ones that work after turning the keep aparts off) seperately on one computer. I've never looked into compositing and seeing as this work needs to be finished ideally by Tuesday I don't have time to learn it unless it's really simple. The same goes for Krakatoa really. I might try lowering the particle count and increasing the shape size of the fire particles for the frames that don't work after turning off the keep aparts and see if that works. If it does then I'll just resubmit the whole job to the render farm again.

Thanks for your help

[Anonymous]

Just tried rendering a frame again around the 1100 frame mark and when it didn't work before with the keep aparts turned off it seems to be working now. Not quite sure what's going on here but hopefully it will stay working.

[Anonymous]

Hopefully you can get through the sequence. Having to re-render certain frames with the keep aparts off will probably give you different shapes and the animation will jump during those frames.

[Anonymous]

That's what I thought but I rendered out a couple of frames earlier with the keep aparts off and on and there's barely any difference. I think this is because the other pflows have barely any particles in the first place. I'm tempted to get rid of them seeing as there's not really a big difference between having them on and off. This should help with rendering times as well, anything past 1000 frames is taking about 15-20 minutes to render.

[Anonymous]

Apparently you were right, it does change when turning off the keep apart operators so what I've done is turned off the other 3 fire pflows and just left the main one turned on, reduced the particles by 100,000 and set the size bigger by 1.5. The fire looked a lot better before but I'm running out of time now. How easy is it to scale particles size over life? I want my initial smoke particles that spawn along the ceiling to get a little bigger as they live on.

Cheers

[Anonymous]

Not hard. Use a scale operator and then keyframe the % and switch the type to one of the relative options and the animation offset to particle age or event duration. Frame 0 on the timeline will be the beginning of the scale animation that gets synced to the particle.

[Anonymous]

Try turning off the collision tests with SDeflector01 while keeping the keep aparts off. That helped here while rendering a sequence that didn't have the fire.

[Anonymous]

Turning off the SDeflector in all of the fire pflows worked a treat and it sorted out my fire as well. So I've kept them off as well as the keep aparts in the 3 fire pflows but turned them back on to give my fire a better shape. The scale thing worked nicely as well so I'm just tweaking a few things and then I'll send it off to the render farm for (hopefully) the last time!

Thanks for all your help again

[Anonymous]

So I sent it to the render farm again after checking through random frames where I had problems before and it all worked fine yet the fire is still disappearing. One frame even came out with no shadows. I'm beginning to think the problem is the render farm because the file works absoultely fine and renders perfectly on one machine. I'll just have to go through once it's done and re-render the dodgy frames.


EDIT: My mistake, it's not working on one computer any more either. Some of them do but some of them don't. I'm just gonna fill in the gap with a playblast from the viewport I'm running out of time.

[Anonymous]

I've uploaded my latest scene would you mind seeing if you can render out any frames between 140 - 149, 170 - 179 and 200 - 209 please? Just to see if it's a problem with Max. Looking at those numbers it's interesting they are failing in groups of 10 because that's how many frames one computer gets sent in the render farm.

Thanks

pre_rendered_scene53_2010.zip

[Anonymous]

So I've had some time to go through your last scene and I think I found the problem. The accel limit in the Flames KA is too high. I changed it from 20 down to 10 and everything seems to be working. I've rendered out 750 frames with just the pflow and none of them were missing the particles.

If you want to test it yourself before you render, hide everything besides the particles and set your pflow to renderable. Set all your render settings to draft, turn off fg, and set the image size to something small like 180x135. Then it should take about a second for each frame and you won't waste more time rendering.

[Anonymous]

I just tried doing this on my laptop at home and it crashed as soon as I clicked render so I'll have to do it uni. Did you change all of the KA Flames or just the main fire one? And did you turn back on the other keep aparts? Also where are the draft settings in the render options?

P.S Seeing as you've helped me constantly as soon as I asked for help you now have an official thank you in my dissertation! Haha

Cheers

[Anonymous]

Actually the accel limit, I put it down to 5. I kept the keep aparts off for the influence systems because there seems to be an issue somewhere in there too. But I changed the accel limit in all the Flames KA.

The render options I was talking about are at the bottom of the rendered frame window (image precision, shadow precision, etc).