Compositing 3DMax Render Elements

[reptar]

Hi, I am having difficulties compositing 3D Max render elements in photoshop. My scene is of a building which has a plant in front. I have rendered the scene without the plant which is fine but i would like to apply a Matte/Shadow material to the entire scene excluding the plant and render this. I am using Vray so i would like to render the plant out seperately and be able to adjust the brightness/contrast of the plant in photoshop. Now, I am unsure as to what render elements to render out. I have tried VrayDiffuseFilter and VrayMatteShadow but for some reason i am unable to put it all back together in photoshop. Any ideas as to what i am doing wrong?

 

Please let me know if you require further explanation.

 

Cheers.

[Tom Hamelrijckx]

In a copy of your Max file, apply a completely black material to everything except the plant, and a bright white (self-illuminating) apllied to the plant. With background on black as well, and GI disabled, this results in a mask for your plant that you can use in Photoshop...

[reptar]

so if i understand this correctly, should i render out everything as one image including the plant, then using a seperate render to create a black/white mask for photoshop to allow me to brighten plant up... that should work

[Tom Hamelrijckx]

That's correct peter, just make sure your black and white are 100% black and white (no gray values)...

[vizfx]

The fastest way is with PSD manager from CEBAS. For the suggested method be careful with pixel blending.

[tozsam]

There is an easier method than this. If I read correctly you are using v-ray than you can give your house and plant a different object ID, (right click your object and go into object properties, at the bottom under G-buffer you find the object ID) so your house should have object ID 1, and your plant should have ID of 2. Then in your render elements add a MultiMatteElement. Change the options at the bottom of the rollout to reflect your object IDs so tick R and G and make sure the numbers correspond with your objects. Then when you render this pass you will have a red house and a green plant (in flat colour) . So only one render is needed which has your beauty pass and the multimatteelement. Then in photoshop with the multimatteelement pass change all the RGB channels to red and you have a white mask for the house, copy this to a new layer and change all channels to green and you have a mask for the plant.

[reptar]

Excellent! worked a treat!