titor Posted February 1, 2011 Share Posted February 1, 2011 Hello everyone ! I'm having some troubles trying to get some informations to put in my shaders. Let me get this clear : -I have a VOPSOP in which I'm getting informations from a paint SOP -I'm using the VOPSOP to spread the painting on a mesh ( a head ) and deform it a bit -Then I'm having a second VOPSOP in which I generate an Alpha based on the point attribute. -I'm exporting a parameter that is supposed to contain the color information I called DestrMatte that is supposed to be my alpha with color. However when i'm rendering with mantra i add an Extra Image Plane based on the variable DestrMatte, but i can't see anything. Where is my mistake ? I can't figure it out. Thanks for your help ! Ps: i attached the file and an Obj which is the head PPs: I'm not sure if i'm posting in the right place, if not can moderators put it where it belongs? Thanks Head_Creepv3_1.hip headv2.rar Quote Link to comment Share on other sites More sharing options...
titor Posted February 1, 2011 Author Share Posted February 1, 2011 Nobody has a lead ? Quote Link to comment Share on other sites More sharing options...
Mario Marengo Posted February 2, 2011 Share Posted February 2, 2011 Nobody has a lead ? At the end of your 2 VOPSops I see 3 point attributes: "Cd" (vector), "Alpha" (float), and "topp" (float). Over in the shader, AFAICT, you're only picking up one of these: "Alpha", and piping it directly to the Of and Af outputs. Finally, over in the "mantra1" ROP, you're adding 2 AOVs (or "deep rasters"): "Alpha" (float) and "MapDisintegration" (vector). So... 1. I don't see any attribute or shader parameter called "DestrMatte" anywhere. 2. Even though the shader is picking up "Alpha" (and using it), it is not exporting it, and so Mantra can't itself pick it up and pipe it to an AOV. To export it so that Mantra can use it, set "Export" to "Always" in the Parameter VOP (see attached). 3. If you intended either of the other two attributes ("Cd" and "topp") to stand for "MapDisintegration" or "DestrMatte" or whatever, then you have to pick them up in your shader and export them as well. I've done this to both in the attached. Once exported by the shader, the rop can pick them up (and rename them to whatever you like). Anyway, that's how the mechanism works, but having said that, keep in mind that Af, Of, Cf, N, P, and Pz, are all automatically available for AOV output (look at the pull down menu for the "VEX Variable" parameter of each AOV and you'll see them). This means that, in your case, since all you're doing with the attribute "Alpha" is assigning it directly to Af/Of, you don't strictly need to manually export them as you could still get at it via the automatic "Af" AOV -- but only because you're currently doing nothing with it inside the shader and so Alpha==Of==Af (which is not usually the case with most attributes, so it's still good to learn how the export business works). HTH Head_Creepv3_1_mgm.hip Quote Link to comment Share on other sites More sharing options...
titor Posted February 4, 2011 Author Share Posted February 4, 2011 Hey Mario, thanks for your answer, I downloaded your file, and I'll look at it tonight but it seems really interesting. See you Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.