Hi there. So, I’ve been working on a 3D model of Disneyland, and I’m running into a problem. One of the structures I’ve been building is the facade of the Haunted Mansion, which looks very much like a Greek Revival mansion you might find in the antebellum South. There’s a lot of ironwork, in keeping with the New Orleans theme of the area, and I’ve been accomplishing that through images UV-mapped to flat surfaces. I use PNGs with transparent areas, and it’s been working just fine…except for one minor issue.
If you look closely, you can see the flat plane that the image is mapped onto. I’ve checked and double-checked–those transparent areas in the image truly are completely and totally transparent, so the image isn’t the problem. (I’ve had the same problem with multiple objects, anyway.) I’ve checked all the material settings–the alpha is set to 0 and so forth. Everything should be fine. I’m just wondering if anyone has any suggestions on how to resolve this.
Thanks so much! I greatly appreciate your time and expertise.
Unfortunately, I do need it to receive shadows, since there’s a large cupola on the roof nearby, and it casts a shadow on part of the ironwork. However, upon reading your post, I tried turning on Shadeless as a troubleshooting exercise–and the problem persisted, oddly enough. I also know it doesn’t have to do with the fact that I’m using AO, since I tried turning it off, and the problem continued.
i think you still have some specularity in the shader setting of the material on. Create gimp pic with alpha and some typed text in it and map it to a plane. Set the texture-out settings to Col, Alpha and instead of MIX to Multiply. Then play around with the specularity setting slider in the shader-settings. Lights will then create such an effect for me. This is simple, big plane in background and transparent one in foreground with this gimp-picture on it. I cannot see any borders of the plane and there is another plane without a texture totally invisible - no borders.
Looks like dialing out Ambient (which was purposely set to 1) resolves the problem, but the thing is, the object is just too dark then. I’ve got diffusion turned all the way up, and there’s a sun lamp and ambient occlusion lighting it…but it’s just too dark. Any suggestions?
EDIT: Actually, no, turning the ambient value to 0 doesn’t help. =( And yes, I’m made sure specularity is set to 0 and so forth. I was also using Emit, which I tried setting to 0, and that didn’t help, either.
What kind of lamps are you using? I thought there was a similar thread a few months ago concerning this, and there had been a solution there ( it escapes me now).
edit: What are your actual material settings? I set a png with area erased alpha in the uv image editor, saved it, then mapped it to orco on the material for the plane. I set it to ‘use alpha’ and set ztransp for the material, with alpha all the way up. I then set the texture to affect col and alpha in the texture mapto panel, and set it to multiply. I tried all the lamps, and didn’t get the ghosting. I was wondering if you were using ray traced transparency instead of straight ztransparency…
I get them same ghosting if my material has any Spec above 0.00 on the shaders panel. Also to add another note: It only occurs at certain camera angles. Straight on and there is no ghosted edge. Angled up from below (like you pic) and I get a ghost. Turning Spec down to 0.00 and ghost goes away. Hope this helps.
Edit: Hey CD your right. SpecTrans on the MirrorTans tab needs to be set to zero. Then you can turn up the regular Spec setting if you want.
Thanks for the suggestions, all. Unfortunately, SpecTrans is already set to 0, so that’s not the problem. I could turn on Shadeless, PapaSmurf, but wouldn’t that make it impossible for other objects to cast a shadow on it?
I was wondering if you were using ray traced transparency instead of straight ztransparency…
Yes, I’m using raytraced transparency. And all I have for lighting is a sun lamp and AO.
Is it also appearing when you save the image as a .TGA with transparent areas?
Good question–I haven’t tried that. It seems like that shouldn’t be the problem, though, since I have checked and double-checked that those areas of the PNG are truly and completely transparent, without even a hint of color.
And just to remind y’all–specularity is indeed set to 0 already.
It might be the AO that is causing it, but just to make sure the alpha value is 0, take one of the pngs into photoshop or gimp, magic wand select the tranparent area, and then clear the selected area. That will tell you at least if it’s just a problem with the alpha channel of the image you are using.
I hate to push this, but try swapping over to just straight ztrans enabled material with the texture affecting alpha - that is what I tested with, and I had no problems. The reason I suggest this is that there is no real reason to use ray traced - you aren’t creating ‘glass’ IOR, you’re just cutting out shapes with the alpha and needing shadows cast onto the material - I would think this would speed up you rendering time considerably with the large scene…
