Shadow Casting and Populations

[bobbystahr]

Help all...I've not run into this before as I've largely had great luck with populations but in the attached image neither the Saguaro Cactii [a population] nor the desert weeds seem to want to cast shadows tho they both do so when loaded as single objects. I the attached image I had a small ammount of luminance on the Cactii as they seemed dark in a previous render[which also had no shadows]. Any idea what's going on. The cactii are an XFROG model from a while back and the desert weeds are actually a dl from the community call Blue Grass I think standing in for scrub desert weeds but is a .tgo.
I'm re rendering the scene with a radically reduced number of Cactii[3 i think] on my workstation and the shadows are already rendered but all were added as single .obj's one at a time.

[Tangled-Universe]

I see the agave and the small dark cactus do cast shadows on the terrain. I presume these are not populations. By the way, they seems to cast shadows from 2 directions?
On topic; strange problem. Did you have raytraced shadows enabled in the "more settings" tab?

[bobbystahr]

   Aaah, the double shadows...yes they were due to the fact I was working on a collaberation and hadn't set the lights myself , Maori had used the Fill Light setup dl able from here some where. I have a preference to a single sun so eventually I turned one sun off.
    RE: the agave and the small dark cactus do cast shadows on the terrain...indeed they are single objects. I did not have Ray Traced shadows enabled in the Clouds or Atmosphere settings but do in the render settings as I was getting the dual shadow on the barrel pincushion cactus.
    My latest render is almost done and will post it in my Rendo Gallery, and it looks fine...the small grass pop still shows no shadow but at it's size I may just not be seeing it...I changed the sun angle for more dramatic shadows and all the other shadows are there though so I was hoping for a bit from the grass/weeds as well....sigh.
     Also I noticed that unless you render with Detail at 1[all I can do in unregistered] you seem to get artifacts/see through on some of the cactii horns...see previous post with image...that was making me nuts till I remembered My leaf resolution problem that I solved by upping the Detsil to 1.. ...

[Tangled-Universe]

Yeah I didn't mean raytraced shadows in atmosphere or clouds, in the rendersettings indeed.
I understand correctly that it was enabled?

[bobbystahr]

Yeah I didn't mean raytraced shadows in atmosphere or clouds, in the rendersettings indeed.
I understand correctly that it was enabled?

Yup.. ...

[bobbystahr]

Well it's done now so have a squint at this.. ...

[schmeerlap]

That looks fine now. Large cacti are casting shadows and you can see good texture detail now. What exactly was the problem in the first render regarding this? I also looked into the problem and was going to suggest you ensure a) that the Do Shadows checkbox was checked in the Render dialog box, b) that the Do Ray Traced Shadows checkbox on the More Settings tab was checked (as suggested by Tangled Universe), c) that the Cast Shadows and Shadows of Surfaces in the Lighting dialog box were both checked, and d) that the Sit On Terrain box in the Population dialog box (Terrain tab) was checked. BTW, I am WeeLaddie from Renderosity; I hope I have at least backed up my criticism of your upload in Renderosity, even though you seem to have the problem solved now.

[Tangled-Universe]

Well, to be critic and honest, the problem is NOT solved
Your grass clump (don't know what it is, sorry) population still isn't casting shadows.
Maybe option 'd' from WeeLaddie/Schmeerlap (you know what the latter means in dutch?) will help.
I had this problem once myself too, but that was very long ago. I recently did a populated scene without any problems.
So maybe somebody from the crew can enlighten us on this

[bobbystahr]

Sorry I should have included the comment I made at my rosity post...here tis:

     I deleted the Saguaro population and replaced it with fewer,but added singly, cacti; moved the sun down to give a more dramatic light; kept Detail at 1 AA at 3, GI relative detail at 2, GI sample quality at 3, did not engage the GI surface details button.

     I should have added there[in fact I just did] that the desert grass was still not apparently casting shadows but if you check the shadow direction they could well be casting shadows on themselves and we just can't see em due to the tiny size of those weeds.. ...

[DeathTwister]

Hay Bobby, humm good question, as I had done just a couple of weeks back the Agavi as a population in a desert as well, but a close up of them and the shadows worked perfect, but I had not messed with a dang lighting gui at all other then it came in as default, so maybe that was why?  But yes it does look good, hope that is for U know what? /smiles.... hahahaaha Mouri is learning I see, when he does get it with tgd2? that boy going to be dangerous, and that is a very good thing as I love the hell out of his art.

DT

[bobbystahr]

That looks fine now. Large cacti are casting shadows and you can see good texture detail now. What exactly was the problem in the first render regarding this?

It's still unresolved as far as this render is concerned with the Saguaro Cactus Pop. Going to do another control on a default terrain later. I'm doing a closeup of the weeds and at lo res they seemed to have shadows so I'm running a check now in Detail 1 etc. As I mentioned at R'osity, the displacement was being wiped out by a small amount of luminance[0.03?] like bump gets wiped out by brightness in Imagine3D, my mesh modeler that I use, so I took it off and the lovely displacement is back.

[Oshyan]

If this is a consistent problem that you can reproduce, it would be very helpful if you could share an example scene, including the models. You can PM or email me to work out details of a transfer off the forums.

Thanks,

Oshyan

[bobbystahr]

Will try and pull it all together and send it tomorrow after the chiropractor app. thanks for the offer of help. I suspect it has to do with populating on top of displacement myself.. ...

If this is a consistent problem that you can reproduce, it would be very helpful if you could share an example scene, including the models. You can PM or email me to work out details of a transfer off the forums.

Thanks,

Oshyan

[schmeerlap]

If it's a problem with previous displacement shaders, maybe the answer is to put a Compute Normal shader between them and the population shader.