New Phong features in R8.1

[LucentDreams]

can you post a pic of what the original app displays and what c4d is displayin.

[JoelOtron]

Thanks Kai--hoped you'd respond!

I really have no idea what the file looked like in the original app. We purchased a pretty expensive model of a human figure into which the entire skeleton, musculature and other tissues fit. Its pretty high poly and I would expect it to render smooth, but it doesnt. I will post a pic of what I have in C4d shortly.

[JoelOtron]

Heres the render in C4d:

[JoelOtron]

The file was converted by the author, and in doing so there is a crappy wireframe. Could be that theres nothing that can be done here, but I thought I'd see what you guys had to say..

[pit]

Hi Joel - silly question, but have you tried converting all those tris to quads? Sometimes it´s as simple as that. Well, just a thought....

[AdamT]

Another silly question: have you tried optimizing the model? Sometimes foreign meshes come in as separate faces, which prevents the Phong tag from doing its thing.

[JoelOtron]

Tried making quads--but what you see is the best that C4d could do. I tried applying it with "evaluate angle" turned off but the result was worse. Optimised a few times (obsessive compulsively) and not much help either.

I think I may need to just ask the company to supply a higher res file if they can. They probably run polytrans or some other conversion software and didn't really pay close attention to how well the resulting mesh turns out.

MV mentioned that the mesh may be too big--which it is. I hadn't resised the model since there are other project files that interlock with this one.

Thanks!

[Mike Abbott]

Joel,
Looking at that mesh there are lots of long skinny quads - some of which are almost certain to be 'non-planar' (twisted). While Cinema normally handles these well, some quads in the mesh look a bit too optimistic IMO. As a test I'd triangulate all faces (this will ensure face planarity), optimise, then render with a smoothing angle-limit of no more than 30 or 40 degrees.

Any better?

Mike Abbott

Just another thought: has the mesh come in a new-with-v8.1 'normals tag'? If so, try it without that.

[JoelOtron]

Thanks Mike!

Haven't tried trainagulating, etc yet--Will do.

Normals tag? If you mean the new phong tag with edge breaks, yes--it came in with that but I turned off edge breaks AND angle limit.

Is there a "normals" tag I may have missed?

[Mike Abbott]

Joel,
No - the tag I'm referring to is the 'Normal Tag'. It's different to the 'Phong Tag'. If you have one of these tags and mouse over it the status bar will give the name. The icon looks like a few polys with 'normal lines'.

The tag shows when an imported mesh includes extra normals info generated by the exporting programme. Rhino and FormZ can export it, I know for certain. It's provides C4D with better normals info - and therefore better shading. You can't add one directly in C4D - so it isn't listed in the C4D Objects > New Tag menu (AFAIK).

I thought you had one of these tags and it might be conflicting with your other (Phong Tag) settings - but I guess not. So, I now think you might need one :)

Could you ask your supplier if he can export a small test mesh 'with normals information' included? Depends what program he's exporting from I guess.

HTH

Mike A.

[JoelOtron]

Thanks--wasn't aware of this normals tag.

[Deestrakt]

well, it may sounds stupid but check the size of your object.
if your object is very big (and that may happen when u import from another format), try to scale it down. try a tiny size.

i once got something similar, and the reason was that my object was very huge. after i scaled it down, it was ok.

[JoelOtron]

Thanks Deestract

That seemed to have done it. Making the model really tiny smoothed the mesh out perfectly when rendered!

Unfortunately the project has become complicated and there are several other c4d proojscts that need to be the same size releative to the human model. I may not have the time or sanity to rescale each project/piece.

A question:

If I were to group all items in a project, including all cameras and all lights, would there be any problems as a result. Does changing the scale of a light or a camera change the rendered result? Which scaling is favorable with: object tool or model tool for lights and cameras?

If I scale all items down together, will I basically have the same "bad mesh" result in rendering, since the model size is still relative to the camera and light size?

Thanks!

[Deestrakt]

Originally posted by JoelD

A question:

If I were to group all items in a project, including all cameras and all lights, would there be any problems as a result. Does changing the scale of a light or a camera change the rendered result? Which scaling is favorable with: object tool or model tool for lights and cameras?

If I scale all items down together, will I basically have the same "bad mesh" result in rendering, since the model size is still relative to the camera and light size?

Thanks!

First, use the Model tool to move/scale/rotate your objects (ie : in modelisation process).
The object tool should be used only to modify position/rotation/size in the animation process (ie for changing size of an object during animation for exemple).

about scaling them down all together, i dont now what will be the result. i'm not sure u'll have the same "bad mesh" result. its mostly the model size that seems to matter.

but now i'm thinking about something else. maybe its related to the shadow map !
i dont have C4D with me now, but theres something about the size of the shadow maps in the lights parameters (in shadow tab most certainly).
then maybe your problem with your "big" model could be solved, not by scaling it down, but by tuning up the size of the shadow map.

maybe its that..

[AdamT]

Originally posted by Deestrakt
but now i'm thinking about something else. maybe its related to the shadow map !
i dont have C4D with me now, but theres something about the size of the shadow maps in the lights parameters (in shadow tab most certainly).
then maybe your problem with your "big" model could be solved, not by scaling it down, but by tuning up the size of the shadow map. maybe its that..
I think you may have hit the nail on the head. Otherwise--if smoothing is being affected by object scale--that's a bug that should be reported.

[JoelOtron]

I have incresased the shadow BIAS and map size in earlier attempts, I upped the bias to 24 (yikes!) and the map to 1500 and that helped a lot but still not perfect. Shrinking the model itself did a better job of smoothing the mesh.

Weird, because usually, I go through the opposite process to smooth an object. Usually an object comes in too small and renders with "jaggies". This is usually corrected by enlarging the mesh significantly.

Is it a bug? I don't know... Seems to me that if you have a scaled object in which the polys are several meters in width/length, there might be smoothing issues. I've had this same problem in other apps.

[Deestrakt]

Originally posted by AdamT
if smoothing is being affected by object scale--that's a bug that should be reported.

still, it raises a point i always wondered about : how do u guys decide about the size of an object when u model it ?

lets say, u model a man. whats the "right" size, if there's one ? 2 meters high ? 20 ? 200 ? 2000 ?

see what i mean ? is it totally up to us or is there a good "proportion" to keep ?

[AdamT]

Originally posted by JoelD
I have incresased the shadow BIAS and map size in earlier attempts, I upped the bias to 24 (yikes!) and the map to 1500 and that helped a lot but still not perfect. Shrinking the model itself did a better job of smoothing the mesh.

Weird, because usually, I go through the opposite process to smooth an object. Usually an object comes in too small and renders with "jaggies". This is usually corrected by enlarging the mesh significantly.

Is it a bug? I don't know... Seems to me that if you have a scaled object in which the polys are several meters in width/length, there might be smoothing issues. I've had this same problem in other apps.

It may be that the map size still wasn't high enough. Could you try rendering with hard shadows, area shadows, or with no shadows at all?

[Deestrakt]

ok, Joel, so u'll try to scale down all the items together ?

i'm curious about the result but i tend to think that it will be ok.

If I scale all items down together, will I basically have the same "bad mesh" result in rendering, since the model size is still relative to the camera and light size?

if its not related to shadow map, but to the size of the model, then maybe its about how the physics of the light (dunno, uuh..how they simulate light particles.. :curious: ) affects the mesh.
if u scale down everything, lights included, the size of your model change, but the "physics" of the lights wont (still guessing).

so maybe u wont have a problem when scaling down everything, since u cant really "scale" a light, right ? i mean, u cant modify the size of an omni light for exemple.

[Brucie Rosch]

I wonder if you could get "bad" smoothing with a mesh created in C4D and then scaled huge? (just a thought)

[AdamT]

I believe (but could be totally wrong) that Phong shading works on the relative angle of face normals, and the relative scale of polygons. If I'm correct, scaling the whole object should have no effect on the smoothing.

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