Render Mask / visible Plants

[daCaMo]

One question. I would like to render individual objects via Render Mask (Object ID). Unfortunately, in outdoor scenes, whole plants or parts of plants are always rendered.

Why is that? How can I get around this? I've already distributed rendertags and turned off "camera visibility". But that's pretty annoying.

The plants always have a different Object ID than the actual object.

[zhanet.georgieva]

Hi daCaMo,

To investigate and address your issue, could you please share your scene here or send it through our support system (Submit a Request) ?

[martin_hennrich]

https://forums.chaos.com/forum/v-ray...in-render-mask

Please check the opacity maps of your vegeatation which cause the render mask problem!

[daCaMo]

https://forums.chaos.com/forum/v-ray...in-render-mask

Please check the opacity maps of your vegeatation which cause the render mask problem!

Great, thank you - that was the solution! I would never have thought of it.
Now I guess I just need to adjust all the plants I bought...

Greetings “from the Pott”!

[daCaMo]

I don't know if it has something to do with the last update or if it never worked before and I just didn't notice it... but the "Alpha from Texture" option no longer works.

The textures are no longer cut out.

[martin_hennrich]

Hi,
Alpha from texture only works if you use a file format which has an integrated alpha channel like psd, tif or png. Just like alpha from difuse. The black and white jpg has no alpha channel, thats why you need to use default for jpgs.

[daCaMo]

Hi,
Alpha from texture only works if you use a file format which has an integrated alpha channel like psd, tif or png. Just like alpha from difuse. The black and white jpg has no alpha channel, thats why you need to use default for jpgs.

Thanks for the info. I didn't know that. During the first tests I probably only paid attention to the masked result and not to the plants that I had already rendered before.

then I can probably no longer use the Object ID function. All my Maxtree and Chaos Cosmos libraries have jpegs as alpha texture.

[zAppledot]

Thanks for the info. I didn't know that. During the first tests I probably only paid attention to the masked result and not to the plants that I had already rendered before.

then I can probably no longer use the Object ID function. All my Maxtree and Chaos Cosmos libraries have jpegs as alpha texture.

daCaMo I was running into the same issue with jpg alpha maps on my plants, and I found that if I switched the sampling to "None" instead of the default "MIP" mode, I was able to get a clean render mask. It seems like the issue is related to the texture sampling. I hope this finding also helps the developers solve the issue.

[wolfgang_himmelfarb]

This feels like a stupid workaround but I just tried adding an object tag and turned off "visible to camera" and it seems to have worked. You would have to then do that for every alpha object.

I cant believe support asked me to add what are clearly bugs to the "feature request portal." If I put "fix render masks" to the portal they will forsure not add it. Its not a feature we want, its a bug we want fixed.... also dont forget, render masts dont work for objects behind refraction.

[zhanet.georgieva]

Hello wolfgang_himmelfarb,

Thank you for bringing this up and for sharing your workaround. I completely understand your frustration and want to clarify the situation.

The issue you’re describing with render masks not working as expected is indeed a bug, not a feature request. I’d like to apologize for the confusion caused in the other thread. The behavior is already logged in our internal system [VC4D-1724], and I’ll make sure its priority is increased.

I’ll keep this thread updated if there’s any progress or additional information on this matter.

Thank you for your patience and understanding.

[wolfgang_himmelfarb]

Hello wolfgang_himmelfarb,

Thank you for bringing this up and for sharing your workaround. I completely understand your frustration and want to clarify the situation.

The issue you’re describing with render masks not working as expected is indeed a bug, not a feature request. I’d like to apologize for the confusion caused in the other thread. The behavior is already logged in our internal system [VC4D-1724], and I’ll make sure its priority is increased.

I’ll keep this thread updated if there’s any progress or additional information on this matter.

Thank you for your patience and understanding.

Thank you for hearing us out. Also I want to add - its the (1)opacity map issue but also render masks don't work for (2)objects behind refractive materials. This means render masks wont work for objects behind glass. The means the only way is to put the glass itself in the render mask, which will always be overkill.

Thank you again!