Is there any way to access the Textures of a material for a Node in a SCNTechnique DRAW_SCENE pass?
I am implementing a custom SCNTechnique. This is primarily for practice with different rendering techniques, so performance is not my goal.
Ideally, if I had full control of the pipeline I (think I) could attach multiple targets and get the albedo, normal, depth in a single pass.
Right now, I am attempting to implement SSAO and (eventually) Deferred Lighting with SCNTechniques.
My SSAO passes will eventually look like the following:
- Render Albedo to Texture, Depth to Texture
- Render Normal to Texture
- Compute Occlusion, combine with Albedo
Right now I am attempting to debug, and am doing the following:
- (attempting to) Render Albedo to Texture
- Render Normal to Texture
- Combining the two for visual confirmation
My Technique has the following definition:
"passes": [
"albedoPass": [
"draw": "DRAW_SCENE",
"metalVertexShader": "albedoVertex",
"metalFragmentShader": "albedoFragment",
"outputs": [
"color": "AlbedoMap",
],
"colorStates": [
"clear": "1",
],
"depthStates": [
"clear": "1",
],
],
"normalPass": [
"draw": "DRAW_SCENE",
"metalVertexShader": "normalsVertex",
"metalFragmentShader": "normalsFragment",
"inputs": [
],
"outputs": [
"color": "ViewSpaceNormalMap",
],
"colorStates": [
"clear": "1",
],
"depthStates": [
"clear": "1",
],
],
"showNormal": [
"draw": "DRAW_QUAD",
"metalVertexShader": "normalsResultVertex",
"metalFragmentShader": "normalsResultFragment",
"inputs": [
"quadOverlayPosition": "quadOverlayPosition-Symbol",
"viewSpaceNormalMapTexture": "ViewSpaceNormalMap",
"albedoMapTexture": "AlbedoMap",
],
"outputs": [
"color": "COLOR",
],
"colorStates": [
"clear": "1",
],
]
],
"sequence": [
"albedoPass",
"normalPass",
"showNormalPass",
],
"targets": [
"AlbedoMap": [
"type": "color",
],
"ViewSpaceNormalMap": [
"type": "color",
],
],
"symbols": [
"quadOverlayPosition-Symbol": [
"semantic": "vertex",
],
],
]
For the albedo pass, would it be possible to acquire the diffuse material in the fragment/vertex shader given to the pass? Like so:
#include <metal_stdlib>
using namespace metal;
#include <SceneKit/scn_metal>
struct VertexIn {
float3 position [[attribute(SCNVertexSemanticPosition)]];
float2 uv [[attribute(SCNVertexSemanticTexcoord0)]];
};
struct VertexOut {
float4 position [[position]];
float2 uv;
};
struct NodeBuffer {
float4x4 modelTransform;
float4x4 inverseModelTransform;
float4x4 modelViewTransform;
float4x4 inverseModelViewTransform;
float4x4 normalTransform; // Inverse transpose of modelViewTransform
float4x4 modelViewProjectionTransform;
float4x4 inverseModelViewProjectionTransform;
float2x3 boundingBox;
float2x3 worldBoundingBox;
};
vertex VertexOut albedoVertex(VertexIn in [[ stage_in ]], constant SCNSceneBuffer& scn_frame [[buffer(0)]], constant NodeBuffer& scn_node [[buffer(1)]]) {
VertexOut out;
out.position = scn_node.modelViewProjectionTransform * float4(in.position, 1.0);
out.uv = in.uv;
return out;
}
fragment float4 albedoFragment(VertexOut out [[ stage_in ]], texture2d<float, access::sample> diffuse [[texture(0)]]) {
constexpr sampler textureSampler(coord::normalized, filter::linear, address::repeat);
float4 color = diffuse.sample(textureSampler, out.uv);
return color;
}
Any help would be appreciated, thanks!
