All posts related to V2
#367698
When rendering a clear object with a slight draft angle to the part we noticed that we where getting strange lines showing in the object (below image to the right). Tried it with various clear materials (wizard high grade glass, low grade glass, an acrylic material) all produced the same results. Then tried creating the object without the draft angle and the problem when away (image to the left). This happens only at specific camera angles to the object. The result with the draft angle doesn't seem correct to me. Is there any reason that this would render this way when the surfaces are not parallel to each other?

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#367699
Neither look correct to me to be honest, I Imagine your problems are caused by separate objects neither intersecting, nor spaced apart. What happens if you move the objects a tiny bit apart from each other? or intersect them? I also recommend that you apply a tiny chamfer to the glass, even if it is barely visible it will be more realistic
#367700
It is one object: imagine a "U" shaped moulded part if you will, no surface transition at the 90 deg. corner. We did test leaving just the right side (straight panel) and does have the same problem. Also, we tested with chamfers or fillets on each edge and no difference. This problem came up using an engineering part with applied draft for moulding imported as a SAT in 3ds Max. At first we thought it was a problem with the SAT file, then we did a quick test with a clean part directly in 3ds Max but the problem is always there. Once you eliminate the draft it gets back to normal--basically the two faces of a transparent panel have to be parallel. Is it a refraction issue? Is it possible that a drafted part would show like that in real world?
#367702
Below a super basic test: object to the right is a standard primitive box, object to the left, converted to poly and widened the back edge to create a wedge (basically added a draft angle).Rendered with basic physical sky. You can see in the left object the stripes along the face. Object is fairly small size (8"x3"x1/8"). Again, not sure if a true glass object in real life would react like that or not...

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#367768
well, i see this same effect also in vray and the cinema-renderers. with increasing ray-depth the effect becomes more prominent. so i'd guess, this would be a refraction thing.
#367778
mashium123, I did a test in 3ds Max with mentalray and I confirm what you are saying, it appears to be common independently from rendering engine. This is interesting, I would try to find a piece of real glass or plastic shaped like that and see what it looks like in real life....

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#367781
Weird indeed. I will get the plastic part in the next month so I can do some photo tests. The question I would have is how will a photographer adjust that to minimize artifacts for a real life photo shoot? Obviously easy for us, we can simply pull a vertex in :D
#367803
Of course, a photo would be nice.. It is likely a real physical phenomenon which feels weird because our brain has no frame of reference (we don't see objects like these often).

I have done a fair bit of testing on Maxwell in my day, and I can say it follows the refraction laws properly and it bends light at correct "snell" angles (both for white light and for dispersed light).

Likely a manifestation of what you see at the base of this glass:
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Let's talk about Maxwell 5.2

Good news, thank you Jochen