[tennet]

Hi! I am rendering a scene using a HDR in the MX environment and I get these "jagged" reflections. Look at the horizon line reflected in the car.

I have tested lots of different settings to get rid of these imperfect reflections and the only thing that seem to work is cranking up the number of subdivisions to about 4 million polys (see lowres render). This shouldn't be necessary though and the voxelization takes ages.

I have tried to render the scene in Maxwell Studio and it behaves the same. I've also tried to put a simple reflective sphere in a scene, using different HDRs, but the sphere also gets the same jagged reflections (if I don't subdivide the sphere to millions of polys first)? The car scene works fine in Cinema 4D AR and Vray, so it must have something to do with Maxwell.

Is this a bug? Anyone else having the same problems? I am using Mac OS X 10.7.3, Maxwell Render 2.6.10.0 (64bit). Let me know if you need any more info. Hope you can help!

Frederik

[Bubbaloo]

Can you post a wireframe too? I think it's all about the polygon smoothing.

[eric nixon]

It looks like a bump map issue, certainly nothing wrong with the geo.

[tennet]

Hi! I have now edited my post above and added a celrender. I am not using any bumpmap in this car paint either. The problem disappears if I increase the number of SubDivs, which is weird?

Attached in this post is a Cinema 4D testrender. It is done using the exact same scene and HDR. The jagged reflections is not there in the C4D-render, so I don't understand what could be the problem with the mesh? Since the problem also occurs when just putting a reflective sphere in an environment, then it seems to be a problem with Maxwell or the environment?

I have also tried to change the Phong-value, but this doesn't help either. Let me know if you need more info, thanks for helping!

/ Frederik

[eric nixon]

If theres no bump map (have you checked the global bump slot) then its very confusing. The issue with the sphere is probably a red herring because spheres (or very curved surfaces) do require extra subdivs generally. If you can send me the whole c4d file I'll have a look, upload it to mediafire and pm the link.

Otherwise just add more subdivs in the areas that need it, I dont expect the render will slow down much.

Looking closely at the c4d render it also has some buggy weirdness going on if you look at that exhaust pipe

[tennet]

The snorkel on the hood looks weird because it still has Maxwell materials applied to it. I only replaced the material on the car paint for this test. I'll PM you a version of the scene soon.

[bograt]

It looks to me like It is just the reflections picking up on the geometry, a bit like when not using a phong tag. Have you played around with the phong settings? how does it respond without a phong tag applied at all?
Check your reflection channel in your maxwell scene tag as well.

[bograt]

Also as far as I can remember phong is embedded into vray (along with blinn and ward) so again this points to the phong tag...

[eric nixon]

Tennet I had a look at your file,

I opened the mxs and it renders jagged like you say, If you select the object and click the recalc button next to smoothing, its all fixed.

I dont know why the phong smoothing got corrupted in the first place, when I open your original c4d file it renders fine here?
I would recommend using a maxwell camera in your scenes because I got an error with the render region tag which was being applied to the scene object.

So perhaps this problem needs further investigation, perhaps theres a bug on the mac side?

[tennet]

Hi Eric,

Thanks for your answer. The 'recalc'-button, is that found in Maxwell Studio? Haven't seen it in Cinema 4D. We have tried to render the scene on two Mac Pros and we get the same jagged reflections on both (not only this scene). It doesn't show in all angles either...

I have also seen and wondered about the render errors (black lines) that occur when using 'Render Region'. Are those caused by adding the Render region-tag to the Maxwell Scene object and not the Maxwell-camera? Good to know, thanks for the heads-up!

Regards,
Frederik

[JDHill]

I dont know why the phong smoothing got corrupted in the first place, when I open your original c4d file it renders fine here?

Eric -- I believe you are using R12, correct? If Frederik is using R13, it could be the same issue as noted here: http://www.maxwellrender.com/forum/view ... 03&t=38245. I found it to be related to hypernurbs, but that does not imply that it could not come into play in other situations as well, by the way. I just checked, and Studio's normals Recalc is indeed capable of fixing the issue (at least in my test scene).

Frederik -- could you confirm whether this does appear to be the problem, and if so, whether Studio's Recalc function also helps in your situation? If so, I can see if we can bring that functionality over to the plugin, as some sort of 'rewrite normals' switch in the plugin's Object Properties tag.

[eric nixon]

Yes I use R12...

[daros]

Hi Eric, we just had the same experience wit some car models. We had to give the car paint surfaces about 3/4 millions poligons too.

[eric nixon]

Well they look realllly nice, it was worth it,
Car paints are an art form because you have to 'push' with r2 to get the laquered look. I'd love to see how my fav carpaint holds up on that scene you've got, sorry thats not a request, just in theory it would be informative.

Actually my cars end up with a huge poly count, mostly due to slack modelling workflow, but c4d and maxwell dont mind.

This car body is by Ivan, http://www.ivan3d.blogspot.co.uk/ cad parts from everywhere.

2 million polys,.. but really I just wanted to post this render, its not finished just a test, want to change those tiny fins at the back..
whats really cool is that in c4d you can drive this car as a fully dynamic rig, steering with the mousewheel at REALTIME, I'm using a gtx 470 card which helps.



Sorry hijack and show-off but I wanted to impress Daros, whose work has really inspired me

[tennet]

Sorry for the late reply, but yes we are using Cinema R13. I checked the other thread and it seems to be the same problem as RichG has. I opened the scene in MX Studio and ran the 'recalc' command and then the problem is gone (see attached).

Hope this will be fixed soon, since it seems to be a quite major bug with Cinema R13 and Maxwell, not being able to render perfect reflections. We also get these black dotted lines when using 'Render Region'. Is this because the RenderRegion-tag is used on the Maxwell Scene-object in C4D (as stated above) or is this also a bug? These lines show up on both Mac and PC renders.

Looking forward to hear from you.

/ Frederik