Jump to content

Weird Effects when using Diffuse +Shadow

Recommended Posts

hey guys , 

im facing a really weird issue here when i stared lighting my 3d character


when i activate shadows and keep the "diffuse" option enabled some lighted color lines show up on the skin :





the diffuse option im talking about :



and its even become worse if i change the "(shadows maps)" from Soft to Hard




any idea why this is happening ?!! and any idea how to fix it ?


Link to post

@Cerbera hey thanks for the replay :)

actually there is nothing fancy in my Materials just a normal skin texture added into "color" channel



and Unfortunately the character in this project is private for a customer 
so i only can upload the lighting setup in my project : 


my lighting setup.c4d

if u could take a look at the lights settings and see if i made a mistake in any of them , i appreciate your help 


and by the way the issue is only showing when i enable the diffuse in this light and not in the other lights in the list 

u'll find it in the file

Link to post

OK, thanks, that rules out the texture as being the cause of this.


Next Step would be to check mesh normals - are they aligned ? Check this by selecting all polys, which should appear orange on the outside. If any polys are blue on the outside you can select all polys, r-click and do Align Normals. Let me know if that solves it...


I can't see anything specific wrong with your lighting, other than that Area lights should ideally use Area Shadows, but I wouldn't expect setting other things there to produce the result you are getting on your mesh, hence me looking for problems there first...


In your test file of course there are no errors to see, which further suggests something in the model may be wrong.

It also looks a bit like the sort of errors you get when there is intersection with another mesh - could that be the case here ?




Edited by Cerbera
added info... pls refresh page
Link to post

For me it looks like some kind of reflexion/specular issue.


As manual say:

"When Diffuse is enabled, the color properties of an object are ignored by the light source, only specular surfacing is produced by the light. "

Link to post
10 minutes ago, bezo said:

For me it looks like some kind of reflexion/specular issue.


As manual say:

"When Diffuse is enabled, the color properties of an object are ignored by the light source, only specular surfacing is produced by the light. "

Surely that should say 'when diffuse is DISABLED, the colour properties of an object are ignored by the light source' ?


After all, when diffuse is on, the diffuse colour in the material does get affected by the light, right ?


Is that a mistake in the manual or a mistake in the way I'm interpreting it ?


I can't see how this could be linked to reflection / specular, because there is only a color channel (diffuse) in the material...



Link to post


looks like the mesh normales in the effected area are current there is no blue polygons there  :/





@bezo hello man , thanks for the replay , 
i dont have reflection in the skin material , so do you mean Diffuse in the light is the problem ? should i disable it ?


Link to post

Indeed, that's that ruled out too then ! :)


Hmmm, what else could that be... what happens if diffuse remains on in the light, but you up the samples from 40 to say, 200  ?




Link to post

@Cerbera   @bezo


when i changed the Shadow Density in the right side light i noticed this : 

from 200 > 500 Density or up




under 100 Density : 



but i lose the dark shadow effect if i do that !! any idea ?


also even when the density is under 100 there still a small line showing up in middle of his Biceps if u can notice in the second picture 



Link to post

The only things I found that made any difference was 1) cranking up the Bias (Abs) distance. When I did this, those harsh lines softened out the higher I went. 2) Increase the sampling radius (max is 20) and then setting the Sampling Radius Boost to High. Perhaps some combination of these two things will be your best solution. I've never mucked about with shadow densities, so I wish you good luck!


Edit: I used the Male T-Shirt preset model with no material applied as a test object.

Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


We are dedicated Cinema 4D Community of friendly and passionate artists, hobbyists and developers. Feel free to join us to share your knowledge, your art and anything that might help Community to grow. We are providing guidance, free plugins and files, feedback, sponsorships and various discounts for our Contributors and much more. :cowboypistol:




  • Create New...

Copyright C4D Cafe © 2021 Powered by Invision Community